ANSWER
The correct answer is: a) Affect
Explanation:
Affect is usually a verb. It means to influence or change something.
Example: The weather can affect your mood.
Effect is usually a noun. It means the result or outcome of a cause.
Example: The new law had a positive effect on the community.
So, when you talk about an action (influence or impact), you use affect (verb).
When you talk about the result, you use effect (noun).