A Molecular Collision Is Sufficiently Energetic to Cause a Reaction,yet

A molecular collision is sufficiently energetic to cause a reaction,yet no reaction occurs.Which of the following is the least likely explanation?

A) The proton-proton interaction is too large
B) The molecules have poor orientation
C) One of the molecules is not moving too slowly.
D) One or both the molecules does not have enough energy.
E) All of the above could be an explanation.