( ) 15. Tom might have come to school in time for Professor Brown's lecture,.

( ) 15. Tom might have come to school in time for Professor Brown's lecture,.
( ) 15. Tom might have come to school in time for Professor Brown's lecture,______ .
A. if he got up earlyB. unless he had got up early
C. but he got up rather lateD. but he had got up so late
是否能选D用过去完成时