We could _______ him with a detached house when he came, but he

We could _______ him with a detached house when he came, but he had specifically asked for a small flat.
A、provide
B、have provided
C、not provide
D、not have provided
【正确答案】：B
【题目解析】：could have done本能够干某事  从but从句看出此句谈论的是过去的情况，主句也是对过去状况的虚拟，所以用could have done形式.