UPSC CDS English Sentence Improvement Part 1 Questions

In the given sentence, the phrase ‘by dinnertime’ must be replaced with ‘till dinnertime’ as the preposition ’till’ is used to talk about something that will keep going on going for a duration of time from a specific time to another whereas ‘by’ to talk about a deadline when something will happen before that time. Thus, option (b) is correct.