The logic followed is: The Assertion is correct because Vitamin D is unique because it can be made in the skin from exposure to sunlight. UVB light from the sun strikes the skin, and humans synthesize vitamin D3, so it is the most “natural” form. Thus we should sit in sunlight for some time every day. The reason is correct because Vitamin D is the only vitamin that can be formed naturally by the body by getting exposed to the sun and that is why it is called the sunshine vitamin. A 5-30 min exposure to the Sun between 10:00 a.m. to 4:00 p.m. results in the formation of a sufficient amount of vitamin D. Thus we can say A and R are true and R is the correct explanation of A. Hence, the correct answer is "Option 3". Additional Information Vitamin Another name Deficiency A Retinoids / Retinol Night blindness B1 Thiamine Beriberi B2 Riboflavin Ariboflavinosis B3 Niacin Pellagra B5 Pantothenic Acid Paresthesia B6 Pyridoxine B7 Biotin B9 Folic Acid B12 Cyanocobalamin C Ascorbic Acid Scurvy D Calciferol Rickets E Tocopherol Crohn's disease K Phylloquinone Bleeding or VKDB (also known as hemorrhagic disease of the newborn)