Answer:
His first fall season in the east had been (A) a delight.
Step-by-step explanation:
The given blank in the question is filled with the word ‘been’. This is because the statement states the past experience of the person. It already contains the word ‘had’ which compliments with the word been. Both these words together states the past experience of the man which was a delight in the east. The experience had already taken place and thus the term had been is used to justify the sentence.