It _____ around nine o'clock whe

It _____ around nine o'clock when I drove back home because it was already dark.
A、had to be
B、must have been
C、was to be
D、must be
【正确答案】：D
【题目解析】：译文：当我回到家时肯定已经九点啦，因为天已经黑啦。本题考查推测用法。肯定性猜测用must。答案为D。