あれ + は / が / を / も / の
あれ means "that over there": a thing away from both you and the person you are talking to. It is a noun, so は and the other particles follow it directly.
It is one of a set of four:
English "that" covers both. Japanese splits it by where the listener is: それ is near the listener, あれ is far from the listener too. For the bag beside the person you are talking to, say それ. For a mountain you are both looking at, それ is wrong and the word is あれ.
Because the thing is far from both people, the answer uses あれ as well.
あれ stands alone. In front of a noun the word is あの: ×あれ車 is wrong.
These go beyond pointing at a thing you can see.
あれ also names a thing both people know from before, though it is not in sight. A thing only one of you knows about is それ.