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’.
Unless someone makes a complaint, they will not clear the garbage from the street.

Correct option is B

The correct substitution of the highlighted words is (b) No substitution required.
Explanation:
The sentence uses “Unless”, which is grammatically and contextually correct here.
· “Unless” means “if not” and is used to introduce the only condition under which the main clause would be true.
· The sentence: “Unless someone makes a complaint, they will not clear the garbage...” → Correctly expresses that no action will be taken unless a complaint is made.
Grammatical Rule Used:
Unless + Present tense, followed by future tense or other main clause outcome.
· Example: Unless it rains, we will go out.
· → (If it does not rain, we will go out.)
Why Other Options Are Incorrect:
· (a) “Without someone makes a complaint” – Grammatically incorrect. “Without” should be followed by a noun/gerund, not a full clause.
· (c) “Despite someone makes a complaint” – Incorrect; “despite” should be followed by a noun/gerund, not a full clause.
· (d) “Except someone makes a complaint” – Incorrect; “except” doesn’t work with conditional clauses.
Final Sentence:
Unless someone makes a complaint, they will not clear the garbage from the street.
This sentence is correct as given, so no substitution is required.