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: Radiology
Radiological investigation in females of reproductive age should be restricted to: 
Select and explain. 
A. First 10 days of menstrual cycle, B. Last 10 days of menstrual cycle, C. 10-20th day of menstrual cycle, D. Period of menstruation
A: First 10 days of menstrual cycle
Answer: A: First 10 days of menstrual cycle 
Explanation: Ans. First 10 days of menstrual cycle