The formation of two different rocks is described below. at depths of thousands of feet, molten rock material cools slowly to form rock a. a volcanic eruption pushes molten material to the surface of earth and the molten material cools rapidly to form rock b. which statement is correct? both rock a and rock b are igneous rocks. both rock a and rock b are metamorphic rocks. rock a is an igneous rock and rock b is a metamorphic rock. rock a is a metamorphic rock and rock b is an igneous rock.