I think the most important reason to reply on evidence in a discussion is for the evidence to support your opinion about something.
Ex:
Your having a disagreement with someone about a question. And you both have evidence that help support your opinion. Those reason help you think that, that's the answer
<h3>
<em>I Hoped That Helped. </em></h3><h3>
<em>I Hoped That Helped. Have a Good day!</em></h3>
Answer:
i think its A but i could be wrong, cause C or D don't make sense..and B kinda doesn't so..yeah