问题详情

According to the passage, what has surprised the author？
A．IPhone: The Missing Manual is the best-seller on computer this year.
B．IPhone is the most popular cellphone this year.
C．The downloadable application is the most successful part of iPhone.
D．The most popular version of iPhone: The Missing Manual is in the form. of application.请帮忙给出正确答案和分析，谢谢！