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?

【正确答案】 A
【答案解析】[解析] 7人中若不包括B和A则剩下5人,因此本题也即为求从5人中选出4人的可能性有多少种,根据组合的基本概念可知共有[*]种可能的选择。