Question

I have a group of five male gerbils. Four of them were litter mates and the other was the father. None have never been separated since the birth of the litter mates. We just recently saw chasing going on in the cage by the same gerbil to only one specific gerbil. So, we took the one being chased out and inspected him for wounds. We found some on his stomach and near his genitals. They didn't look extremely bad, from in my own experience I have seen worse. We immediately removed him from the tank and cleaned them with saline solution with a q-tip. I know this is probably a dominance issue since they are getting older now, but what I wanted to know is if I should either (a) remove the bully and put him in a cage by himself and put the one that was chased back, (b)Remove the chased wounded one and place him in a cage alone, or (c) Remove wounded gerbil and place in new tank with another non-bully member from his group so he is not alone. Since, gerbils alone don't live as well or as long.