There are over 2,000 different enzymes in the human body. Which statement best describes why it is necessary for there to be so many different kinds of enzymes?

A.
Some enzymes will not react with any type of substance.
B.
Each enzyme catalyzes only a certain reaction or set of reactions.
C.
All enzymes can catalyze any reaction in the human body.
D.
Enzymes are constantly being used up in reactions.