In elastic collision, A is conserved while in inelastic collision B is conserved.
I. Momentum
II. Kinetic Energy
III. Potential energy
$\begin{align}
  & \text{A}\text{. A=I,II} \\
 & \text{ B=I} \\
 & \text{B}\text{. A=I,III} \\
 & \text{ B=I} \\
 & \text{C}\text{. A=III} \\
 & \text{ B=II,III} \\
 & \text{D}\text{. A=II} \\
 & \text{ B=I,III} \\
\end{align}$

Hint: Collisions – define it in terms of the laws of conservations they follow. Explain the types of collision based on the conservation laws they followed. Use the law of conservation of momentum and the law of conservation of kinetic energy in an elastic collision to develop the theory of one-dimensional elastic collision.

Complete answer:
Collision can be defined as the event in which two moving bodies or one moving body and one at rest collide with each other.

Collision is of two types –
a.)Elastic collision
b.)Inelastic collision

Elastic collision can be defined as a collision where the total kinetic energy of the system is conserved. In an elastic collision both the total kinetic energy and the total linear momentum of the system remains constant.

In an inelastic collision the total kinetic energy of the system will not be conserved. The total kinetic energy before the collision and after the collision will be different. Momentum is conserved in the inelastic collision but we cannot track the kinetic energy through the collision because some of the kinetic energy is converted to other forms of energy.

There is no dependence on the potential energy conservation for both elastic and inelastic collisions.
So, we can say that in elastic collision both the kinetic energy and momentum is conserved and in inelastic collision only the kinetic energy is conserved.

So, the correct answer is “Option A”.

Note:
Most of the collisions in our day to day life are inelastic collisions. We have a special case of inelastic collision which is called the perfectly inelastic collision. In this type of inelastic collision, the two objects will stick together.