Mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the following questions.
Nam’s score on the test is the highest in the class; he _________ hard last night.
A. should have studied
B. may have to study
C. must have studied
D. could have studied
Chọn C
“must have done st”: nhận định một việc đã xảy ra trong quá khứ