Pellagra occurs in population dependent on:

Ans. C. MaizeMaize hasZein protein which is deficient of tryptophan. And Pellagra, characterized by 3D's (Diarrhea, Dementia and Dermatitis) is due to the deficiency of Niacin in the body. Niacin is synthesized by tryptophan (essential amino acid). So people whose staple diet is maize, are more prone to Pellagra.