Which statement about oceanic plates relative to continental plates is true?

• A. Oceanic plates are thicker and less dense than continental plates.
• B. Oceanic plates have the same thickness and density as continental plates.
• C. Oceanic plates are thinner and denser than continental plates.
• D. Oceanic plates are not involved in subduction.

Answer: (C)

Oceanic plates are thinner and denser than continental plates. This combination means they sit lower in the mantle and are more prone to sinking beneath lighter crust at boundaries. Oceanic lithosphere is formed at mid-ocean ridges and, as it moves away and cools, becomes denser and thicker only in a relative sense; its crust is basaltic and dense, while continental lithosphere has a thicker, buoyant felsic crust that is less dense overall. Because oceanic crust is denser, it can subduct beneath continental crust at convergent boundaries, creating trenches and volcanic arcs. The other statements don’t fit because oceanic plates are not thicker and less dense, they do not have the same thickness and density as continents, and they are involved in subduction, not excluded from it.