In which sentence is the underlined word a gerund?

C. Breathing is a basic function controlled by the brain.

Explanation:

A gerund is a verb that functions as a noun.

In this sentence, "Breathing" is both a verb and a thing. (Noun = person, place, or thing)

b. cronkite, a trusted television personality, declared that the war was unwinnable and told the american people that the government had better find a way out

even though it went against everything the news anchors typically stood for, cronkite voiced an opinion and took a stance, telling the us that there was no way they were going to win, the war was going to end in a stalemate.