Classify the actions based on how they could affect a reaction rate.

Add a catalyst

- would increase rate of reaction;

Because adding catalyst would lower activation energies.

Decrease the concentration of a reactant

- would decrease rate of reaction; because there would be less molecule

Decrease the surface area of a solid reactant

- decrease rate of reaction; less collisions because more particles would become isolated

Increase the temperature

- Would increase reaction; Because it would accelerate the movement of the particles and make them colliding faster