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 required’.
The state authorities seemed rather callous regarding the movement of workers during the Covid-19 lockdown.

Correct option is B

The correct substitution of the highlighted words is "No substitution required".
The original phrase accurately conveys the sense of indifference or lack of concern by the state authorities without needing any changes.
Grammatical rule involved:
· Rule: Prepositions like "regarding" are used to link nouns, pronouns, or phrases to other words within a sentence, thereby providing additional details about time, location, or in this case, context or subject matter.
· Rule: Noun phrases consist of a noun and any modifiers including adjectives, modifiers, or determiners. They function as subjects, objects, or complements in sentences and should be clear and concise.