Which Is NOT True About Cofactors Involved in Enzymatic Reactions

Multiple Choice

Which is NOT true about cofactors involved in enzymatic reactions?

A) They may alter the conformation of the enzyme.
B) They may be a metal such as iron.
C) They may be a substrate in a catalyzed reaction.
D) There must be equal quantities of enzyme and cofactor molecules for a reaction to proceed.
E) Only a small number of cofactor molecules may be needed to maintain enzyme activity.