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’.
Clearing the entrance examination for universities abroad was the biggest challenge of my life.

Correct option is D

The correct substitution of the highlighted words is (d) No substitution.
Explanation: The sentence is in simple past tense, referring to a completed action. "Was the biggest challenge" is grammatically and contextually accurate.
Grammatical Rule Used:
· Use simple past for completed actions in the past.
· Superlative adjective (biggest) is correct with "the".
Example: Climbing the mountain was the toughest task of his life.
Information Booster: Avoid using “has been” or “is” when the time frame is clearly in the past.