Reactions can be speeded by increasing the proportion of reactant molecules which collide with proper orientation. This can be accomplished by.........

A)compressing the reactant mixture.
B) heating the reactant mixture.
C) addition of a catalyst.
D) cooling the reactant mixture.

A will work IF the reactants are gases.

B will work because it gives the molecules more energy.
C will work to increase the rate of reaction because the activation energy is lowered.
D generally decreases the rate.