Which type of rock is considered dominant in oceanic crust?

Correct answer: Basaltic

Oceanic crust is mainly associated with basaltic rocks. Basalt is a dark, dense volcanic rock formed when molten material cools, often at or near the ocean floor. New oceanic crust is produced at mid-ocean ridges, where magma rises, cools, and becomes basalt. This composition also helps explain why oceanic crust is generally denser and thinner than continental crust, which is more commonly linked with granitic rocks.

Option B is therefore correct. Granite is chiefly associated with continental crust, while limestone and sandstone are sedimentary rocks that may occur in layers but do not form the dominant basic material of oceanic crust. The most useful school-level association is “basalt with ocean floor” and “granite with continents.” Although oceanic crust can contain sediment and other minor materials, its major rock type is basaltic. Hence the correct choice is basaltic, not granitic, limestone, or sandstone.