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
↑ energy linear acceleration used in- 
Select and explain. 
A. X-ray, B. Cathode rays, C. Photon rays, D. α - rays
A: X-ray
Answer: A: X-ray 
Explanation: X-ray tubes produce X-ray by accelerating electrons to high energies.