Answer: A.
Explanation: Proteins are made by decoding genetic information carried by DNA, but contain no genetic information themselves. Although the sequence of amino-acids in a protein matches the code in DNA, there is no process for using protein as a template for DNA.
Proteins may be structural, like collagen in tendons or keratin in hair and fingernails, or enzymes active in metabolism, or in transport, such as haemoglobin that transports oxygen, or in transporting ions into and out of cells against a concentration gradient.
