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': 'Radiological investigation in a female of reproductive age sould be restricted to : \nSelect and explain. \nA. Period of mestruation, B. First 10 days of menstual cycle, C. Last 10 days of menstrual cycle, D. 10th to 20th day of ccle', 'role': 'user'}, {'content': 'Answer: B \nExplanation: First 10 days of menstual cycle', 'role': 'assistant'}]