The correct option is A niacin
Niacin is a vitamin that acts as a part of coenzymes (NAD, NADP) which serve as hydrogen acceptors and donors for many enzymes. Its deficiency in the body causes pellagra which is characterized by dermatitis (skin inflammation), diarrhoea and dementia (nervous disorder). Deficiency of tocopherol (vitamin E) leads to destruction of RBCs. Deficiency of riboflavin (vitamin B2) causes inflammation of eyes, sores on the lips and skin diseases. Folic acid deficiency leads to anaemia and failure of RBCs to mature.