This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Biochemistry
[{'content': 'Rate limiting enzyme in catecholamine synthesis? \nSelect and explain. \nA. Dopa decarboxylase, B. N-methyltransferase, C. Dopamine hydroxylase, D. Tyrosine hydroxylase', 'role': 'user'}, {'content': "Answer: D \nExplanation: Ans. is 'd' i.e., Tyrosine hydroxylase", 'role': 'assistant'}]