The Recycling System for Amino Acids in the Body Is

The recycling system for amino acids in the body is primarily used to:​

A) provide fuel for the cells to spare glucose.
B) convert nonessential amino acids into essential amino acids.
C) ​provide the cells with materials to build body proteins.
D) ​add protein to muscles when there is a shortage of energy from foods.
E) ​produce immune proteins.