Select the most appropriate option to substitute the highlighted segment in the given sentence. If there is no need to substitute it, select ‘No substitution’.
It was the biggest jump in earnings for me and I was delighted.

Correct option is D

The correct substitution is (d) No substitution.
Explanation: The sentence is in simple past tense, indicated by “was” and “I was delighted.” The phrase “the biggest jump” appropriately refers to a past event.
Grammatical Rule Used:
In past tense narration of an event that is complete, we use was/were + adjective/noun to indicate the superlative event in the past.
Example: That was the most exciting match of the season.
Information Booster: Using present perfect ("has been") would change the timeline to recent past with relevance to the present, which is not needed here.