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 major difference between X-Rays and Light is: 
Select and explain. 
A. Energy, B. Mass, C. Speed, D. Type of wave
A: Energy
Answer: A: Energy 
Explanation: The main difference between an X-ray photon and a visible light photon lies in the energy of each photon. Xray photon has approximately 5000 times the energy of an ordinary light photon, allowing the Xray photon to pass through materials more readily than a regular light photon. Ref: Techniques in Microscopy for Biomedical Applications By Terje Dokland, Page 289