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': "Gonadal sex of the fetus is determined by : \nSelect and explain. \nA. Secretion of testosterone, B. Secretion of antimullerian hormones, C. Sex determining region on the 'Y' chromosome, D. Secretion of estrogen", 'role': 'user'}, {'content': "Answer: C \nExplanation: Sex determining region on the 'Y' chromosome", 'role': 'assistant'}]