Select the most appropriate option that can substitute the highlighted segment in the given sentence to improve it. If no improvement is required, select ‘No improvement required’.
I will definitely return your notes at Saturday evening.

Correct option is A

The correct substitution of the highlighted words is (a) return your notes by.
· The preposition "by" is correctly used when referring to a deadline or the latest time something will be done. The phrase "by Saturday evening" indicates that the action will be completed no later than that time.
· Grammatical rule used: The preposition "by" is used to indicate the latest time at which an action will be completed. It is often used to set a deadline.
· Example: "Please submit the report by Friday afternoon." Here, "by" is correctly used to set the deadline for submission.