This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: vitamins, Subject name: Biochemistry
[{'content': "Casal's necklace' is seen in the following disease \nSelect and explain. \nA. Beri-Beri, B. Scurvy, C. Pernicious anemia, D. Pellagra", 'role': 'user'}, {'content': 'Answer: D \nExplanation: The Casal necklace is an erythematous pigmented skin rash in the distribution of a broad collar (dermatomes C3 and C4). It is seen in patients with pellagra. It occurs as a result of niacin (vitamin B-3) deficiency. Pellagra is a disease characterised by diarrhoea, dermatitis and dementia. Ref : Biochemistry by U. Satyanarayana 3rd edition Pgno : 138-141', 'role': 'assistant'}]