The address resolution protocol is a broadcast that says "hey buddies, I have this layer 3 address, does anyone of you bear the same address?" If any host has such ip address, it responds with "hey man, I heard someone is looking for my physical address, take, this is it". Of course every frame has source and destination field but that's not part of the response of an arp like you stated. Also I said the information you provided was would be useful to me. Thanks anyways