Answer:
A. Mass
Explanation:
Inertia of an object is the resistance of the object to any change in its state of motion: it means that if an object is at rest, it tends to stay at rest for inertia (unless a net force acts on it), and if it is moving, it tends to continue moving with the same velocity, for inertia.
The inertia also describes how difficult it is to stop/accelerate an object, and it is directly proportional to the mass of the object: in fact, the larger the mass of an object, the more difficult it is to change its state of motion, and this means it has greater inertia.
