单项选择题

Questions 1 to 5 are based on an interview. At the end of the interview, you will be given 10 seconds to answer each of the following 5 questions.
Now listen to the interview.
In this special school, how many children usually are there in a class

A.5 or 6.
B.30 or 40.
C.7 to 10.
D.13 to 14.