How Did the Maria Form

How did the maria form?

A) Large impacts formed craters, which were immediately filled with lava from the Moon's molten core.
B) Large impacts formed craters. The impacts themselves melted the surface rock, and this eventually solidified to form the maria.
C) Large impacts formed craters. Later, radioactive decay melted portions of the Moon's upper interior, and this moved upward to fill the craters.
D) The Moon's surface was molten and unstable after its formation. Parts of the surface collapsed to form the maria.