The physical quantity which is the product of mass and velocity of a body is known as
Momentum
Explanation for correct option
Momentum, the product of the mass of a particle and its velocity. Momentum is a vector quantity; i.e., it has both magnitude and direction.
So, the correct option is C.
Explanation for incorrect options
Option A:
Inertia, the property of a body by virtue of which it opposes any agency that attempts to put it in motion or, if it is moving, to change the magnitude or direction of its velocity. It is represented by product of mass & square of the distance. So, this option is incorrect.
Option B:
A force is a push or pull upon an object resulting from the object's interaction with another object. It is given by the product of mass & acceleration. So, this option is incorrect.
Option D
Energy is the ability to do work. So, this option is incorrect.
Therefore physical quantity which is the product of mass and velocity of a body is known as momentum i.e; option C is correct.