In Many Organelles,groups of Different Enzymes Are Located on Membranes

In many organelles,groups of different enzymes are located on membranes in close proximity to each other.Why?

A) Attaching enzymes to the membrane prevents the cell from losing them to the surrounding environment.
B) When enzymes are in close proximity, each one can catalyze more than one type of reaction.
C) These enzymes are involved in the same metabolic pathway; keeping them closer together increases the pathway's efficiency.
D) All enzymes must act in groups to sufficiently reduce the amount of activation energy needed for a reaction to occur.