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
Which among the following is produced by a linear accelerator? 
Select and explain. 
A. X rays, B. Beta rays, C. Gamma rays, D. Neutrons
A: X rays
Answer: A: X rays 
Explanation: Linear accelerator is source of powerful x-rays. The name linear accelerator comes from the fact that electrons are produced in the machine and accelerated in a straight line. They then smash into a metal target within the machine and, because the energies involved are so high, produce high energy x-rays. Cyclotron is used to produce Gamma rays.