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: Unknown
[{'content': 'Investigation of choice for endometrial svnechea is- \nSelect and explain. \nA. Endometrial sampling, B. Hysteroscopy, C. Colposcopy, D. Ultrasound', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans-B', 'role': 'assistant'}]