which of the following is a true principle of inertia?\na it is a force that causes objects to move.\nb it…

Brief Explanations:

Inertia is the tendency of an object to resist changes in its state of motion. Option A is wrong because inertia is not a force. Option B: Inertia is related to mass (more mass means more inertia), but saying it's "proportional" in the way B implies is incorrect as inertia is a property, not a directly proportional quantity in that sense. Option D is wrong as inertia exists regardless of friction. Option C correctly describes inertia as the tendency to resist (change) motion, like changing backward motion (resisting the change from backward to another state or maintaining backward motion unless a force acts).

Answer:

C. It is the tendency of an object to change its backward motion.