Explanation: In linguistics, a root word holds the most basic meaning of any word. It's what's left after you remove all the affixes (the prefixes and suffixes). The root "fac" most likely means "to do or make" we can know this by looking for the meaning of words that contains this root, for example: factory, manufacturer, benefactor, etc. All these words express the idea of doing something, or acting, so the correct answer is option C.
The best answer that I would choose is to do or make because in a factory that's basically what you do there and you have to think of the meaning of words in order to answer questions like this.
