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
Radioactive substance emits the following except – 
Select and explain. 
A. Gamma, B. Beta, C. Alpha, D. X–rays
D: X–rays
Answer: D: X–rays 
Explanation: Linear accelerator:- X-ray, electron beam.
Radioactive nuclide :- Gamma rays and particulate radiations (Alpha particles, Beta particles, Positrons, neutrons).