Select the most appropriate option to substitute the highlighted segment in the given sentence.
Rohan exercised and ate a lot, lest he should not be weak.

Correct option is D

The correct substitution of the highlighted segment is ‘lest he should be weak.’
· Explanation: The word ‘lest’ is followed by ‘should’ without using ‘not’, as the negative sense is already implied in ‘lest.’
· Correct Sentence: Rohan exercised and ate a lot, lest he should be weak.
Grammatical Rule Involved:
· ‘Lest’ introduces a clause that expresses a negative purpose or fear. It is always followed by the modal verb ‘should’ and does not require an additional negative word.

Structure
Main Clause + lest + Subject + Verb (bare infinitive / sometimes with 'should')

Why Other Options Are Incorrect:
· (a) lest he should not weak: Grammatically incorrect; missing the verb "be."
· (b) lest he would be weak: Incorrect because ‘lest’ requires ‘should,’ not ‘would.’
· (c) lest he would not be weak: Incorrect; the negative sense is already included in ‘lest.’