The setting of a story effects the story's plot.

This question tests affect vs. effect and subject-verb agreement.

Affect is a verb meaning "to influence" (like affecting someone's mood), while effect is a noun meaning "a result" (like the effect of rain). Since "setting" is singular, the verb needs an -s ending to match.

Option 1 → Wrong verb form, missing apostrophe, and unnecessary plural.

Option 2 → Perfect! Correct verb with proper -s ending and possessive.

Option 3 → Uses noun "effects" instead of verb, plus wrong plural.

Option 4 → Missing the -s ending that singular subjects require.