单选题 Ben and Ann are among 7 contestants from which 4 semifinalists are to be selected. Of the different possible selections, how many contain neither Ben nor Ann?

A、 5
B、 6
C、 7
D、 14
E、 21

【正确答案】 A

【答案解析】The number of possible selections of 4 semifinalists that do not contain Ben or Ann is equal to the number of possible selections of 4 semifinalists from the remaining 7-2 = 5 contestants, which is equal to