Tuftsin Is a Tetrapeptide That Stimulates and Promotes the Destruction

Tuftsin is a tetrapeptide that stimulates and promotes the destruction of tumor cells.What is meant by the term tetrapeptide?

A) There are four separate peptide chains in its structure.
B) Four peptide bonds join the amino acid together in its structure.
C) Four amino acids are present,joined together by peptide bonds.
D) Four different secondary structures are present.
E) This protein has a quaternary level of structure.