Answer:
D. We had taken an early flight to Denver before we realized we were a day early for the meeting.
Explanation:
From the options given in the question, the use of the subject- verb agreement in all of the sentences A, B and C are wrong. The sentence is in the past perfect tense. Options A, B and C had wrongly used the "perfect" form of the verb as "took, take, taken (without the 'had')". The mistakes in the sentences are as follows-
A. We had took an early flight to Denver before we realized we were a day early for the meeting.
B. We had take an early flight to Denver before we realized we were a day early for the meeting.
C. We taken an early flight to Denver before we realized we were a day early for the meeting.
So, with the use of "had", the verb has to be in the past participle form. Thus, the correct sentence is-
D. We <em><u>had taken</u></em> an early flight to Denver before we realized we were a day early for the meeting.
