______________________, I would have given you his address.. A、 If you asked meB、 You had asked meC、 Should you have asked meD、 Had you asked me

步骤 1：分析句子结构
句子的主句是"I would have given you his address"，这是一个虚拟语气的句子，表示与过去事实相反的假设。因此，从句需要使用过去完成时态。

步骤 2：确定从句的正确形式
从句的主语是"you"，谓语动词是"ask"。在虚拟语气中，与过去事实相反的假设，从句使用"had + 过去分词"的形式。因此，从句应该是"Had you asked me"。

步骤 3：排除其他选项
A选项"If you asked me"是与现在事实相反的假设，不符合题意。
B选项"You had asked me"是陈述语气，不符合虚拟语气的要求。
C选项"Should you have asked me"虽然使用了虚拟语气，但"should"表示的是"应该"，不符合题意。