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': 'All are true regarding selective estrogen receptor down–regulator (SERD), Fulvestrant except: \nSelect and explain. \nA. Used for treatment of advanced breast cancer, B. Is a selective estrogen antagonist, C. Is slower and short acting and less safer than SERMs, D. Administered as once a month i.m. dose', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]