Physics for IGCSE & O level - Forces And Motion (Section 9 - No. 18)
Inertia is best described as...
The force that causes objects to fall to the ground.
The tendency of an object to resist changes in its motion.
The force that opposes motion.
The rate at which an object changes its velocity.
Explication
Inertia is the tendency of an object to resist changes in its motion.