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: Gynaecology & Obstetrics
[{'content': 'Which of the following is used as surrogate for endogenous LH surge in IVF \nSelect and explain. \nA. IGF, B. GnRH, C. HCG, D. hmg', 'role': 'user'}, {'content': 'Answer: C \nExplanation: HCG is used as surrogate for endogeneous LH surge in invitro fertilization.', 'role': 'assistant'}]