Answer:
First of all, we can immediately eliminate the first option, as completely dismissing the other sides argument without explanation is a bad move and can put you in a tough spot.
A concession would simply be giving up and letting the other side win, and your goal is to win the argument, not just forfeit it, so we can also dismiss this option.
Before we go over the correct answer (number 3) I wanted to explain why you shouldn't follow up with a rebuttal. While introducing the counterclaim, you want your attack to be focused, and if you make a counterclaim, for example, "apples are good for you and not cereal" and then rebutted the other sides argument that cereal is good for you, your attack may come off as less focused and a little too aggressive.
And that is why number 3 is correct, you can say, "apples are good for you and not cereal, because a study from 2015 saw an decrease in common illnesses from people who regularly ate apples."
Please tell me if I have read the question wrong!
Cheers!
-Fibo