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
X-rays were discovered by - 
Select and explain. 
A. Godfrey Hounsfield, B. Roentgen, C. Coulomb, D. Sievert
B: Roentgen
Answer: B: Roentgen 
Explanation: X-ray were discovered in 1895 by W.C. Roentgen.