Question 250·Easy·Form, Structure, and Sense
A set of new guidelines ______ to reduce light pollution and protect nocturnal wildlife.
Which choice completes the text so that it conforms to the conventions of Standard English?
For Standard English subject–verb agreement questions, first strip away prepositional phrases (like "of new guidelines") to find the core subject and decide whether it is singular or plural. Then, check that the answer choice (1) provides a complete finite verb, not just an -ing form or infinitive, and (2) matches the subject in number; avoid being distracted by nearby plural nouns that are not the true subject.
Hints
Find the subject
Before looking at the answer choices, decide what the main subject of the sentence is. Is it "set" or "guidelines"?
Check number (singular vs. plural)
Once you know the subject, ask: Is that subject singular or plural? Your verb should match that number.
Decide if the sentence is complete
Think about whether the blank must be filled by a main verb. Would a form ending in "-ing" or starting with "to" finish the sentence as a complete statement by itself?
Match the subject and verb form
Of the options that can act as a complete verb, pick the one whose form correctly matches a singular subject in the present tense.
Step-by-step Explanation
Locate the true subject of the sentence
Ignore the extra words for a moment and focus on the core structure:
- "A set of new guidelines ______ to reduce light pollution and protect nocturnal wildlife."
The main noun is "set", and "of new guidelines" is just a prepositional phrase describing what kind of set. So the subject is singular: a set.
Decide what kind of word is needed
After the singular subject, we need a main verb to form a complete sentence. That verb should tell what the set does in relation to "reduce light pollution and protect nocturnal wildlife."
So we are looking for a verb form that:
- functions as the main verb (not just a descriptive phrase), and
- matches a singular subject.
Eliminate choices that are not main verb forms
Look at the endings and structures of the choices:
- A base verb (no "-s") is usually used with plural subjects (they) or with "I/you."
- A verb ending in "-ing" usually needs a helping verb (like is or are) to be a complete predicate.
- An infinitive beginning with "to" (like "to aim") often shows purpose but does not act as the main finite verb by itself.
Remove any options that would leave the sentence without a clear, complete main verb after the subject.
Match the remaining verb to the singular subject
Now focus on subject–verb agreement:
- The subject is singular: A set.
- With a singular subject in the present tense, the verb form ending in -s is correct (like she runs, the team wins).
Therefore, the only choice that provides a finite verb and agrees with the singular subject "A set" is "aims".