Mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the following questions.
You ______ so politely at the party. Everyone was casually dressed
A. mustn't have dressed
B. needn't have dressed
C. couldn't have dressed
D. didn't need to dress
Đáp án B
needn't have dressed: không cần làm gì nhưng vẫn làm