问题详情

Why does the administrative assistant say this:
A．He jokes that the student may not smile for some reason.
B．He suggests that perhaps the student is physically unable to smile.
C．He implies that it is difficult to smile when up against the cream wall.
D．He indicates that many students tend not to smile when posing for pictur请帮忙给出正确答案和分析，谢谢！