When the Concentrations of the Reactants Are Increased,the Rate of the Reaction

When the concentrations of the reactants are increased,the rate of the reaction increases.This is best explained by

A) an increase in the fraction of molecules that have enough energy to react.
B) an increase in the rate constant.
C) an increase in the average potential energy of the molecules.
D) an increase in the frequency of the molecular collisions.
E) an increase in the kinetic energy of the molecules.