In the presence of a catalyst, the heat evolved or absorbed during the reaction: 

1. Increases.

2. Decreases.

3. Remains unchanged.

4. May increase or decrease.

HINT: Catalysts do not alter the enthalpy change of the reaction.

Explanation:

In the presence of a catalyst, the heat absorbed, or evolved during the reaction remains unchanged as there is no change in stability of reactant and product. It only alters the rate of reaction but doesn't affect any thermodynamic properties of the reaction.

Thus, option 2 is the correct answer.