In the Collision Theory of Reaction Rates, Which of the Following

In the collision theory of reaction rates, which of the following accounts for the largest portion of the observed temperature dependence?

A) As temperature increases the rate of collisions between the reacting molecules increases.
B) More molecular collisions exceed some minimum energy when the temperature increases.
C) There are many collisions in which the molecules are not properly oriented to result in reaction.
D) The electrons in the reacting molecules are moving faster at higher temperatures.
E) None of these.