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
Velocity of x-rays are: 
Select and explain. 
A. 1 lakh miles/sec., B. 2 lakh miles/sec., C. 3 lakh miles/sec., D. 0.5 lakh miles/sec.
B: 2 lakh miles/sec.
Answer: B: 2 lakh miles/sec. 
Explanation: None