This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Phenylalanine and Tyrosine metabolism Detail, Subject name: Biochemistry
[{'content': 'All of the following are tyrosine derivatives, EXCEPT \nSelect and explain. \nA. Serotonin, B. Melanin, C. Epinephrine, D. Thyroxine', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Melanin, Catecholamines (Dopamine, Norepinephrine, Epinephrine), Thyroxine are the derivatives are tyrosine. Serotonin is a tryptophan derivative.', 'role': 'assistant'}]