Choose the option that best completes the gap(s).
I knocked at his door, but he .......
A
has already left
B
left already
C
would already leave
D
had already left
Verified Correct Answer: D.
Grammar & Contextual Explanation
'knocked' signifies a past tense. The past perfect tense is required to complete the sentence.
Source: Myschool Past Questions Archive (Record #12373)