Answer:
They
Explanation
You don't know who they is
Hi !!
1- Those are grils. (<em>subject plural)</em>
2- Chad is wrong. <em>(subject singular)</em>
<em>-</em>
<em>☺☺☺</em>
C. The mediator is the answer because even though the question is trying to gauge whether you know the meaning of the word mediator, it is also providing a grammatical solution to itself. None of the other words fit in that sentence correctly except for mediator, and also the word mediator (someone who is keeping peace between differing parties) fits the actions the sentence is proposing.