Amino Acids in Proteins Are Linked to One Another by Peptide

Amino acids in proteins are linked to one another by peptide bonds between the

A) methyl group of one amino acid and a side group of another amino acid.
B) carbon atoms of two adjacent amino acids.
C) carboxyl group of one amino acid and the amino group of another.
D) nitrogen atom and carboxyl ion.
E) phosphate group and nitrogenous base.