by I’d have bought Sam’s car if I’d known he was selling it.
A. I knew Sam wanted to sell his car.
B. I didn’t buy Sam’s car because I didn’t know he was selling it.
C. I bought the car without knowing it was Sam’s.
D. I’ll buy the car as soon as Sam decides to sell it.
Câu trả lời là: B là đáp án đúng
