Which action would reduce the activation energy of a chemical reaction?

The activation energy can be lowered by the addition of a catalyst.

Catalyst is a substance which speeds up the reaction without itself used up in the equation.

The catalyst will be produced as it is at the end of the reaction.

Activation energy is the minimum energy that is needed for the particles which are undergoing the reaction. This energy is required by the molecules to undergo collision which leads to the chemical reaction.

The hill in the picture shows the activation energy which the molecules should possess to undergo a chemical reaction.

On adding the catalyst this energy gets lowered and the more molecules even with lesser quantity of energy can undergo the reaction.

the product of the pressure and volume is also constant