Answer:
Gravity is best described as a fundamental force.
Step-by-step explanation:
Gravity is one of the 4 fundamental forces(3 of the forces out of 6).
The description of mass is independent to Gravity. Since an objects mass determines the strength of the pull of Gravity. But it is not Gravity itself.
Molecular pull is more of a density determination. For example the pull between the atomic particles of a solid is stronger than those of a gas.
Thrust is a kind of acceleration. It is the push and resist to the drag force.