This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Molecular Genetics, Subject name: Biochemistry
[{'content': 'Serotonin is derived from - \nSelect and explain. \nA. Tyrosine, B. Phenylalanine, C. Alanine, D. Tryptophan', 'role': 'user'}, {'content': "Answer: D \nExplanation: Ans. is 'd' Le., Tryptophan", 'role': 'assistant'}]