How do igneous rocks form?

A. from the evaporation of water

B. from the modification of existing rock

C. from the cooling of magma

D. from the cementing of sediments

C. from the cooling of magma

Igneous rocks form from the cooling of magma (option C). When molten magma cools and solidifies, it forms igneous rocks. This process can occur beneath the Earth's surface, leading to intrusive igneous rocks, or on the Earth's surface, resulting in extrusive igneous rocks. The cooling rate of magma affects the texture of the rock, with slower cooling allowing for the growth of larger crystals.