When should the man check with Student Services to

单项选择题

Questions 4 to 6 are based on the following conversation. At the end of the conversation, you will be given 15 seconds to answer the questions.
Now, listen to the conversation.

When should the man check with Student Services to ensure the change of registration date

A．When all of the senior students register in courses.
B．Twenty-four hours before the registration date.
C．Seven days before the designated registration date.
D．Twenty-four days before the registration date.