Which term is used as a verb to indicate influence?

The term that is used as a verb to indicate influence is "affect." When you use "affect" in a sentence, it typically refers to the action of making a change or having an influence on something. For example, if you say that one factor affects another, you are implying that the first factor has an influence on the second, which aligns with the meaning of the question.

Understanding the nuances of the other terms is helpful context. "Effect," for instance, is primarily used as a noun meaning the result or outcome of a change, rather than as a verb. "Impact" can be used as both a noun and a verb, but it often conveys a more forceful or significant influence rather than just any influence. "Result" is also primarily a noun that denotes the outcome of an action or event, rather than an influence itself. Therefore, "affect" is the clearest choice that directly indicates the act of influencing something.