Answer : 1. "Retinol"
Explanation :

Answer: A) Retinol Explanation: Vitamin A is a group of unsaturated nutritional organic compounds that includes retinol, retinal, retinoic acid, and several provitamin A carotenoids. IUPAC Name :: (2E,4E,6E,8E)-3,7-dimethyl-9-(2,6,6-trimethylcyclohexen-1-yl)nona-2,4,6,8-tetraen-1-ol   Vitamin Name - Chemical Name Vitamin A   -     Retinol Vitamin B1  -    Thiamine Vitamin B2  -    Riboflavin Vitamin B3  -    Niacin Vitamin B5  -    Pantothenic acid Vitamin B6  -    Pyridoxin Vitamin B7  -    Biotin Vitamin B9  -    Folic acid Vitamin B12  -   Cyanocobalamin Vitamin C     -   Ascorbic acid Vitamin D     -   Calciferol Vitamin E      -   Tocoferol Vitamin K      -   Phylloquinone and Menaquinones