Answer: A. enough kinetic energy and favorable geometry
Explanation: According to collision theory, the rate of a reaction depends upon the number of effective collisions which means the collisions which result in the formation of product which in turn depend on following two factors:-
a) Energy factor: In order for a collision to be successful, the colliding molecules must cross a energy barrier which is called as threshold energy. Thus molecules with energy less than threshold energy are not able to result into products.
b) Orientation factor: the colliding molecules must have proper orientations at the time of collision otherwise they do not result in product formation.
