A.
If he registered for the wrong class
B.
If he could not attend the class
C.
If he was dissatisfied with the class
D.
If he rescheduled the class
正确答案:B
译文
Read an email.

Subject: Photography class
Dear Mr. Clark,
Unfortunately, the photography class you registered for on October 20 has been rescheduled. It will now meet on October 28 at 6:00 P.M. instead of October 26 at 5:00 P.M. Your registration fee will be refunded if you have a scheduling conflict.
Regards,
Emily Rodriguez