This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Metabolism of protein and amino acid, Subject name: Biochemistry
[{'content': '"Indican" is a metabolite of \nSelect and explain. \nA. Histidine, B. Tryptophan, C. Tyrosine, D. Valine', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Indian is a major excretory product in the metabolism of tryptophanRef: DM Vasudevan - Textbook of Biochemistry, 7th edition, page no: 242, fig 18.11', 'role': 'assistant'}]