The new policy had a positive ______ on the students.

• A. affect
• B. outcome
• C. effect
• D. influence

Answer: (C)

The sentence needs a noun that names the result produced by the policy. A natural, precise way to say that is “positive effect on the students.” Here, effect is the noun form of the verb affect, and “positive effect on” is a common, idiomatic collocation to describe a beneficial result. Using affect would be incorrect because that word is typically a verb in this position, not a noun. Outcome and influence are less natural choices in this exact structure: outcome can feel more like an overall result of a process, and influence suggests a shaping force rather than a direct, concrete result. So the best fit is effect.