I don't understand why the answer isn't c. The passage doesn't mention anything about battle.

Kieki, the critical thing to note in the passage is whether or not the "screen time" activity is spent individually, or done with another person. A and B are individual activities, whereas C is a team effort. According to the passage, the type of game or show being seen does not really matter in stimulating aggression.

Only the first 3 choices are showing for me.

This question only has three choices, you may have to pick more than one.

Just to clarify, this passage said that in order for one of these activities to be beneficial to reliving stress/aggression, it must be done WITH another person? It is not simply two people fighting that does the trick? That is why A, along with B, is the correct answer?

Maggie, right.

It explicitly states that two player video games decrease aggression. Why then would a computer staging a battle against two people increase aggression? And it also stated that it didn't matter if they were cooperative or not. So why is A correct?

Mike, you might have misread the answer choices. It's not "computer staging a battle against two people", but "watching a computer ...". The act of watching (A) is solitary, as is (B) battling a computer. According to the passage, it is the solitude / isolation that increases aggression.

I understand that B is one of the right answer.

But what sort of sentence makes A the right answer?

watching is an activity that you could do with only yourself. But play,or we say, FIGHT with another PERSON will release aggression. This question is tricky.