The Activation Energy in the Arrhenius Equation Can Best Be

The activation energy in the Arrhenius equation can best be described as

A) a numerical description of the amount of energy released by colliding reactant molecules when they form products.
B) a factor which corrects for the conversion between J and kJ.
C) a numerical description of how often molecules collide with the proper orientation to react at a specific concentration.
D) the probability that a collision between molecules will have the correct relative orientation for reaction to occur.
E) a numerical description of the amount of energy needed by colliding reactant molecules in order to form products.