Question

I would have told him the answer had it been posible ,but I ____so busy then.

A had been B were C was D would be
请问选什么为什么，谢谢

Answer 1

C was

I would have told him the answer had it been posible ,为虚拟语态，而but I ____so busy then.为非虚拟语气，then提示是过去，故选was