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
The quantity of X-rays is controlled by: 
Select and explain. 
A. Kilovoltage, B. Milliamperage, C. Total filteration, D. Exposure time
B: Milliamperage
Answer: B: Milliamperage 
Explanation: None