In cities all over the United States, workers spend several hours a day in cars crawling along in traffic to get to offices many miles from home. They experience stress, waste time, and pay a lot for gas, car maintenance, and parking. Once they get to work, they make their way through a maze of cubicles, each with its computer, phone, and file cabinet. Nancy Alley, human resources manager at TBWA Chiat Day, doesn"t. She stays at home, talking with managers over the phone and faxing in paperwork. Instead of walking down the hall to chat with coworkers, she E-mails them. Nancy is a telecommuter, someone who works some or all of the time at home. Since 1990, the number of U.S. telecommuters has grown from 4.2 million to 9.2 million. Highway congestion, the high cost of office space, federal clean-air laws, reduced work forces, and lifestyle. needs—all these factors contribute to the growth of telecommuting. What makes it possible is technology. Desktop and laptop personal computers, networking, videoconferencing, fax machines, E-mail, and multiple phone lines provide the fast and efficient communication required for telecommuting. The experiences of many companies suggest that telecommuting can increase workplace flexibility and enhance productivity. At Georgia Power Company, for example, a pilot telecommuting project was so successful that the company decided to triple its number of telecommuters. The company reduced the cost of leased office space by 100,000 a year, increased productivity among the telecommuting employees of its customer service center, and saved the workers a combined 750 commuter miles a day. Telecommuting, however, is not without its obstacles. At one computer software firm, the information systems manager offered telecommuting as an option to her 100-person staff. After three months, the staff members reported that being away from the office was counterproductive to their work. Programmers missed being able to drop by analysts cubicles with questions, and everyone re-ported they were interrupted at home more often. As part of its cost-cutting initiative, Nestle required 140 sales employees to telecommute. Facing many technical problems with telephone lines and frustratingly slow computer networking, most of these telecommuters found it an annoying experience. Telecommuting also makes many employees feel isolated and out of touch, leading to decreased motivation and less, not more productivity. By blurring the barriers between work and family, telecommuting often leads to more work hours and more interference with family life. Telecommuting is not universally applicable. Jobs and individuals must be suitable, and staff must be capable of managing telecommuters. In addition, technological improvements, such as high-speed modems, are crucial. Few people expect to conduct business regularly from a tropical island or mountain resort any time soon.In the passage, the author introduces his topic byA．explaining a phenomenon.B．raising an argument.C．posing a contrast.D．using an example.

In cities all over the United States, workers spend several hours a day in cars crawling along in traffic to get to offices many miles from home. They experience stress, waste time, and pay a lot for gas, car maintenance, and parking. Once they get to work, they make their way through a maze of cubicles, each with its computer, phone, and file cabinet. Nancy Alley, human resources manager at TBWA Chiat Day, doesn"t. She stays at home, talking with managers over the phone and faxing in paperwork. Instead of walking down the hall to chat with coworkers, she E-mails them. Nancy is a telecommuter, someone who works some or all of the time at home. Since 1990, the number of U.S. telecommuters has grown from 4.2 million to 9.2 million.
Highway congestion, the high cost of office space, federal clean-air laws, reduced work forces, and lifestyle. needs—all these factors contribute to the growth of telecommuting. What makes it possible is technology. Desktop and laptop personal computers, networking, videoconferencing, fax machines, E-mail, and multiple phone lines provide the fast and efficient communication required for telecommuting.
The experiences of many companies suggest that telecommuting can increase workplace flexibility and enhance productivity. At Georgia Power Company, for example, a pilot telecommuting project was so successful that the company decided to triple its number of telecommuters. The company reduced the cost of leased office space by $100,000 a year, increased productivity among the telecommuting employees of its customer service center, and saved the workers a combined 750 commuter miles a day.
Telecommuting, however, is not without its obstacles. At one computer software firm, the information systems manager offered telecommuting as an option to her 100-person staff. After three months, the staff members reported that being away from the office was counterproductive to their work. Programmers missed being able to drop by analysts cubicles with questions, and everyone re-ported they were interrupted at home more often. As part of its cost-cutting initiative, Nestle required 140 sales employees to telecommute. Facing many technical problems with telephone lines and frustratingly slow computer networking, most of these telecommuters found it an annoying experience. Telecommuting also makes many employees feel isolated and out of touch, leading to decreased motivation and less, not more productivity. By blurring the barriers between work and family, telecommuting often leads to more work hours and more interference with family life.
Telecommuting is not universally applicable. Jobs and individuals must be suitable, and staff must be capable of managing telecommuters. In addition, technological improvements, such as high-speed modems, are crucial. Few people expect to conduct business regularly from a tropical island or mountain resort any time soon.
In the passage, the author introduces his topic byA．explaining a phenomenon.
B．raising an argument.
C．posing a contrast.
D．using an example.