The resistance in an object that causes it to resist changes in its motion is called:

The correct answer is Inertia. Inertia is a fundamental property of matter, described by Newton's First Law of Motion, which states that an object will resist changes to its state of motion. This means an object at rest tends to stay at rest, and an object in motion tends to stay in motion with the same speed and in the same direction unless acted upon by an unbalanced force.

• Friction is a force that opposes motion between surfaces in contact, not the inherent resistance to change in motion.
• Gravity is a fundamental force of attraction between any two objects with mass, not the resistance to changes in motion.
• Momentum is the product of an object's mass and velocity, representing the quantity of motion, not the resistance to changes in it.