Question

what is the best definition of inertia? an objects resistance to a change in motion the velocity of an object

Explanation:

In physics (a subfield of Natural Science), inertia is defined as the tendency of an object to resist changes in its state of motion. The second option, "The velocity of an object", is incorrect because velocity is a measure of an object's speed and direction, not related to inertia. The first option matches the definition of inertia.

Answer:

A. An object's resistance to a change in motion