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 not a cause for primary amenorrhea? \nSelect and explain. \nA. Sheehan's syndrome, B. Kallmann's syndrome, C. Mayer Rokitansky Koster Hauser syndrome, D. Turner syndrome", 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]