If you wanted to get a better grade, it would have been wise to start earlier.

16/30

You could have started earlier if you had wanted a better grade.

You had better started earlier to get the grade you wanted.

You should have started earlier if you wanted a better grade.

You might have started earlier for a slightly better grade.

Giải thích

A. could have started: diễn tả khả năng trong quá khứ

B. had better started: sai ngữ pháp (phải là had better + V-inf).

C. should have started: lẽ ra nên bắt đầu sớm

D. might have started: có thể đã bắt đầu

Ta có: should have + V3/ed = lẽ ra nên làm trong quá khứ.

Câu gốc: If you wanted to get a better grade, it would have been wise to start earlier.

= You should have started earlier if you wanted a better grade.

Dịch: Nếu bạn muốn đạt điểm cao hơn, bạn nên bắt đầu sớm hơn.

= Bạn nên bắt đầu sớm hơn nếu bạn muốn đạt điểm cao hơn.