Answer:
a. 40%
Explanation:
The continental crust covers 40% of the Earth's surface.
At 25 to 70 km, continental crust is considerably thicker than oceanic crust, which has an average thickness of around 7–10 km. About 40% of Earth's surface area and about 70% of the volume of the Earth's crust is the continental crust. Most continental crust is dry land above sea level.
