Without a doubt, it's A's deer.

A few times over the years we have had to follow a blood trail after one of 'us' fired the shot. It never occured to any of us that the killing shot gets the deer. We are always there to help our buddies. That could mean help dressing a deer, help dragging a deer or help finding a wounded deer. We help each other, never getting into a pissing contest of who's deer it is.

That's what friends do!