The Purpose of Proteins in the Diet Is to Supply

The purpose of proteins in the diet is to supply necessary amino acids.All of the following are true about these amino acids EXCEPT

A) they are stored in "amino acid banks" for later use if they are not needed immediately
B) they are broken down and used to make glycogen or fat if they are not needed immediately
C) they are used to synthesize the specific proteins that are needed by the body at any given time
D) about half of the amino acids are essential in the diet because the body is unable to synthesize them from other amino acids