Mass movement
choose one:
a. is a gravity-driven downslope movement of natural materials.
b. can't happen underwater because the buoyancy force of water is too great.
c. is more likely to happen under dry conditions than under wet conditions.
d. happens only when the slope of a hill gets steeper than the angle of repose

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 ) .

landlessness of ordinary people

^^something like that^^^