He did not arrive until the meeting was nearly over,for the simple reason is that he ____asleep

问题描述:

He did not arrive until the meeting was nearly over,for the simple reason is that he ____asleep
He did not arrive until the meeting was nearly over,for the simple reason is
that he _____ asleep while watching television.
a.had fallen b.has
fallen c.fell d.was falling
我在网上找了,有选A的有选C的 到底应该选什么?并请说明理由谢谢

He did not arrive until the meeting was nearly over, for the simple reason is that he _____ asleep while watching television.a. had fallen b. has fallenc. felld. was falling我在网上找了,有选...。。。但是我们老师给的答案是C。。问他他又解释不清楚选项a是【过去完成时】,过去完成时的概念就是表【过去的过去】,即:他在会议将要结束时的【先前/过去的过去】睡着了才导致他【后来】开会迟到,你说是吗?