<span>These nonessential elements, which can be words, phrases, or clauses, are set off with commas. Rule: Use commas before and after nonessential words, phrases, and clauses, that is, elements embedded in the sentence that interrupt it without changing the essential meaning.</span>
Answer : C) It summarizes the main topic of the essay
It would better improve the paragraph because it has nothin to do with the rest of the paragraph. The paragraph seems to be about team sports and promoting it, while sentence 3 is about individual sports are better then team sports. So removing sentence three would better promote CO-ED team sports.
Broadly speaking, liberty is the ability to do as one pleases