Some people think they have an answer to the problems of automobile crowding and pollution in large cities. Their answer is the bicycle, or "bike".In a great many cities, hundreds of people ride bicycles to work every day. In New York Cith, some bike riders have even formed a group called Bike fie a Better City. They claim that if more people rode bicycles to work there would be fewer automobiles in the downtown section of the city and therefore less dirty air from car engines.For several years this group has been trying to get the city government to help bicycle riders. For example, they want the city to paint special lanes—for bicycles only—on some of the main streets, because when bicycle riders must use the same lanes as cars, there may be accidents. Bike for a Better City feels that if there were special lanes, more people would use bikes.But no bicycle lanes have been painted yet. Not everyone thinks it is a good idea. Taxi drivers don't like the idea—they say it will slow traffic. Some store owners on the main streets don't like the idea—they say if there is less traffic, they will have less business. And most people live too far from downtown to travel by bike.The government has not yet decided what to do. It wants to keep everyone happy. On weekends, Central Park—the largest open space in New York—is closed to cars, and the roads may be used by bicycles only. But Bike for a Better City says that this is not enough and keeps fighting to get bicycle lanes downtown. Until that happens, the safest place to bicycles may be in the park.Question：The main idea of the passage is to show .A.the problems of automobile crowding and pollution in large cityB.bike for a Better City's answer to the problems of automobilesC.a great many bike riders in New York CityD.the city government's decision about bicycle lanes