IIIIITHE1IIIII on 26 July 2012
Well, in that case it seems like person B was harmed for no reason while person C wanted to defend him. Person C didn't harm A without reason, while person D's only reasoning should be to defend A's actions, unless D wasn't aware of C's motivation (defending).
Assuming that B wasn't able to defend himself, C did the right thing while A and D had no reason to hit anyone.
