One Way a Vitamin Can Act as a Coenzyme Is

One way a vitamin can act as a coenzyme is to

A) bind to a substrate to help it find its enzyme.
B) bind to the enzyme so the enzyme can change its shape and bind to its substrate.
C) bind to the outside of a cell,so an enzyme can enter and carry out reactions.
D) bind to another vitamin,signaling a cell to activate its enzymes.
E) replace the activation-energy-lowering activity of a missing enzyme.