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: Pharmacology
[{'content': 'Mechanism of action of tamoxifen is: \nSelect and explain. \nA. Has androgenic receptor blocking action, B. Inhibits enzyme 5α-reductase, C. Has partial agonist and antagonist action on estrogen receptors, D. Inhibition of FSH and LH release from the pituitary', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]