While reading the newspaper, ______.A. a colorful advertisement caught my eyesB. my attention was attracted by an advertisementC. I was attracted by a colorful advertisementD. What attracted my eyes was a colorful advertisement

步骤 1：分析句子结构
句子的主语是 "I"，谓语是 "was reading"，宾语是 "the newspaper"。因此，句子的主干是 "I was reading the newspaper"。接下来，我们需要分析选项，看哪个选项可以作为句子的状语，且符合语法和语义。

步骤 2：分析选项
A. a colorful advertisement caught my eyes
这个选项的主语是 "a colorful advertisement"，谓语是 "caught"，宾语是 "my eyes"。这个选项不能作为句子的状语，因为它的主语和谓语与原句的主语和谓语不一致。

B. my attention was attracted by an advertisement
这个选项的主语是 "my attention"，谓语是 "was attracted"，宾语是 "by an advertisement"。这个选项也不能作为句子的状语，因为它的主语和谓语与原句的主语和谓语不一致。

C. I was attracted by a colorful advertisement
这个选项的主语是 "I"，谓语是 "was attracted"，宾语是 "by a colorful advertisement"。这个选项可以作为句子的状语，因为它的主语和谓语与原句的主语和谓语一致。

D. What attracted my eyes was a colorful advertisement
这个选项的主语是 "What attracted my eyes"，谓语是 "was"，宾语是 "a colorful advertisement"。这个选项不能作为句子的状语，因为它的主语和谓语与原句的主语和谓语不一致。

步骤 3：选择正确答案
根据以上分析，选项 C 是正确的，因为它可以作为句子的状语，且符合语法和语义。