Answer:
B
Step-by-step explanation:
I have never heard of volcanoes on Mercury, and there couldn't be water since it would evaporate immediately. This means it either creates its own heat or it's because it's so close to the sun. Now, if you think about it, we don't create our own heat, we only trap it. So it is safe to assume that it's so hot because it's so close. Hope this helps!