This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Fundamentals in Radiology, Subject name: Radiology
[{'content': 'Regarding CT scan all are true except - \nSelect and explain. \nA. 50% reduction in kVp reduces 50% radiation dose, B. Decrease in mA (milli amperes) decreases radiation dose exposure significantly in pediatric chest, C. Quality of the radiation generated depends upon voltage, D. Radiation dose exposure is directly related to the time of exposure', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Quantity of exposure (radiation dose) is directly propoional to (kVp)2 so reducing kVp by 50% will reduce the radiation dose to 25 % (i.e 75% reduction in radiation dose)', 'role': 'assistant'}]