The Rate of a Chemical Reaction Increases with an Increase

The rate of a chemical reaction increases with an increase in temperature.Which of the following correctly explains why?

A) At higher temperatures,the activation energy is increased.
B) At higher temperatures,the activation energy is decreased.
C) At higher temperatures,more reactant molecules are present and collisions occur more frequently.
D) At higher temperatures,reactant molecules move faster,collide more often,and produce more effective collisions.
E) At higher temperatures,a catalyst is usually present.