When and where to go for the holiday_____yet. A.have not been decided B.has not been decided

题目

When and where to go for the holiday_____yet. A.have not been decided B.has not been decided
请问选什么?为什么

答案

B
When and where to go for the holiday
这个句子作主语,由于是一句而不是多句,所以谓语用单数
整句话意思是,什么时间去旅游,去哪里旅游还没有决定