A peptide bond (amide bond) is a covalent chemical bond formed between two molecules when the carboxyl group of one molecule reacts with the amino group of the other molecule, causing the release of a molecule of water ($H_2O$), hence the process is a dehydration synthesis reaction (also known as a condensation reaction), and usually occurs between amino acids. The resulting $C(O)NH$ bond is called a peptide bond, and the resulting molecule is an amide. The four-atom functional group $-C(=O)NH- $ is called a peptide link. Polypeptides and proteins are chains of amino acids held together by peptide bonds, as is the backbone of DNA.
Ans : (C)