问题详情

Questions 15 to 18 are based on the following dialogue happened in a bookstore.
Why didn"t the man believe his eyes？
[A] Because he didn"t know the price.
[B] Because he didn"t see the price tag.
[C] Because medical texts are usually expensive.
[D] Because the price is too high.请帮忙给出正确答案和分析，谢谢！