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': 'Which among the following is not a SERM ? \nSelect and explain. \nA. Flutamide, B. Ormeloxifene, C. Tamoxifen, D. Raloxifene', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]