天山-7-14

请问下面这题

Not one of the potential investors is expected to make an effort to buy First Interstate Bank until a merge agreement is signed that includes a provision for penalties if the deal were not to be concluded.

1. is expected to make an offer to buy First Interstate Bank until a merge agreement is signed that includes a provision for penalties if the deal were

2. is expected to make an offer for buying First Interstate Bank until they sign a merge agreement including a provision for penalties if the deal was

3. is expected to make an offer to buy First Interstate Bank until a merge agreement be signed by them with a provision for penalties if the deal were

4. are expected to make an offer for buying First Interstate Bank until it signs a merge agreement with a provision for penalties included if the deal was

5. are expected to be making an offer to buy First Interstate Bank until they sign a merge agreement including a provision for penalties if the deal were

答案是A，但one of后面可以用is 么，同时deal后面用were对否？

A of B 的单复数问题在论坛上有许多帖子讨论过，需要看实际意思

虚拟语态