All of the Following Are Concepts Associated with the Theory

All of the following are concepts associated with the theory of plate tectonics EXCEPT:

A) large- scale geologic activity occurs at or near plate boundaries.
B) interiors of plates are geologically inactive and noted for lack of earthquakes and volcanoes.
C) the outer portion of the Earth is composed of rigid units called plates.
D) plates move very slowly, on the order of a few centimeters per year.