Humans Are Unable to Get Metabolic Energy from Cellulose Because

Multiple Choice

Humans are unable to get metabolic energy from cellulose because:

A) cellulose contains very little chemical energy.
B) cellulose is not part of a normal diet.
C) cellulose digesting enzymes are absent from the human gut.
D) cellulose does not taste good.
E) cellulose is present in large quantities in the gut.