Select whichever preposition or determiner you consider the most appropriate for the blank space.
I saw Nandini ___________ she was waiting for the bus.

Correct option is B

The word that can be filled in the blank is ‘while’ to make the sentence grammatically and contextually correct.
· ‘While’ is a conjunction used to indicate that two events are occurring at the same time. Grammatical rule involved: Conjunctions are used to connect clauses or sentences.
· As per the context, the word ‘while’ fits very well, indicating that the action of seeing Nandini happened simultaneously with her waiting for the bus, hence it is the correct option.
Meanings of other given words:
· During: This preposition indicates a period of time in which an event occurs but does not specify simultaneous actions.
· On: This preposition typically refers to a position above something or a day in the week; it doesn’t convey simultaneous actions.
· For: This preposition is used to indicate purpose or duration but does not express the idea of two actions occurring at the same time.
· Thus, all the other given words have different meanings and do not fit in the context of the sentence.