Riboflavin deficiency causes which of the following diseases?

1. A

   Pellagra

   (a) Pellagra. This is the niacin (vitamin B3) deficiency disease with diarrhoea, dermatitis and dementia. It is not caused by riboflavin lack.

2. B

   Scurvy

   (b) Scurvy. Bleeding gums and poor wound healing follow vitamin C (ascorbic acid) deficiency, not riboflavin.

3. C

   Beri Beri

   (c) Beri Beri. Dry or wet beriberi is the thiamine (vitamin B1) deficiency syndrome, unrelated to riboflavin.

4. D

   Cheilosis

   (d) Cheilosis. Riboflavin is vitamin B2. Its deficiency produces angular stomatitis, glossitis and cheilosis—cracks and inflammation at the angles of the mouth. That clinical picture is the official key; pellagra, scurvy and beriberi each map to a different vitamin.

Summary. Official key is (d) Cheilosis. Riboflavin (vitamin B2) deficiency shows as cheilosis and related oral lesions. Pellagra is niacin deficiency, scurvy is ascorbic-acid deficiency, and beriberi is thiamine deficiency. The keyed option is the only disease on the list that is classically tied to B2. Neighbouring B-complex names are frequent exam twins and should not be swapped.