detailed solution

Correct option is C

For a collision to be effective, energy barrier and orientation barrier to be cleared.

The minimum additional amount of energy required by reactant molecules to participate in a reaction is called activation energy$\left({\text{E}}_{\text{a}}\right)$ .

Energy alone does not determine the effectiveness of the collision. The reacting molecules must collide in proper manner in order to occur a reaction.

As concentration increases no of collisions also increases, causes the

increase in rate of reaction.