Concept:A polypeptide is a chain of amino acids linked by peptide bonds.Explanation:Amino acids join together through condensation reactions to form peptide bonds. A short chain is a peptide, while a longer chain is called a polypeptide. Proteins are natural polymers made up of one or more polypeptide chains. Hence, among the given options, protein is a polypeptide. Starch and glycogen are polysaccharides, and fats are lipids.Answer:C. Protein