By the time the plane reaches Harare; it _________ in the air for twelve hours

Choose the word(s) or phrase(s) which best fill(s) the gap. By the time the plane reaches Harare, it __________in the air for twelve hours

A. has been
B. would be
C. would have been
D. should be

Correct Answer:

Option C – would have been

Explanation

‘would have been’ is the correct answer. It shows the possible future action