This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Autacoids, Subject name: Pharmacology
[{'content': 'Which of the following is a selective progesterone receptor modulator \nSelect and explain. \nA. Tamoxifen, B. Ulipristal, C. Nomegestrol, D. Toremifene', 'role': 'user'}, {'content': 'Answer: B \nExplanation: SPRMS- Selective progesterone receptor modulators ulipristal, asoprisnil, proellex-new drugs Ulipristal used for emergency contraception Ref: KD Tripathi 8th ed', 'role': 'assistant'}]