Why is basalt a sign that the moon once had magma at its surface14 points

The basalt is a sign that the Moon once had magma at its surface because the basalt is a type of rock that forms directly from the cooling off of the magma. The basalt is part of the igneous type of rocks, which are the type of rocks that form from the cooling of the magma, be it on the surface or inside the ground, so having basalt on the Moon is a sure sign that our natural satellite once had magma on it.

the answer to your question is c