Answer:
A. is a gravity-driven downslope movement of natural materials.
Explanation:
Mass movement -
It is also called , the slope movement , mass wasting .
it is a process , by which , the sand , rock , soil , regolith move towards downslope by the force of gravity .
It includes , slides , falls , topples , creep .
Mass movement is observed in planets other than Earth , like the Mars , Jupiter , Venus .
Hence , from the given option , the correct option for the definition of Mass movement is ( A ) .