Ans 3: (Master Answer)
The correct answer is B.
In the given Venn diagram X, Y and Z represent vitamin D, vitamin E and vitamin K, respectively. Deficiency of vitamin A causes night blindness and deficiency of vitamin C causes scurvy. Pellagra is caused by deficiency of vitamin B3. Vitamin B is a group of several vitamins like B1, B2, B3, B6, B12 and folic acid and is known as vitamin B complex.