This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Fertilization and Development of Embryo, Subject name: Anatomy
[{'content': 'Outer cell mass gives rise to? \nSelect and explain. \nA. Embryo proper, B. Trophoblast, C. Syncytiotriophoblast, D. None', 'role': 'user'}, {'content': "Answer: B \nExplanation: Ans. (b) TrophoblastRef: Longman's embryology 10th ed., p 38, Longman's medical embryology 12th / 37-40", 'role': 'assistant'}]