This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Physics of Radiotherapy, Subject name: Radiology
Maximum penetrating rays: 
Select and explain. 
A. Alpha, B. Beta, C. Gamma, D. Delta
C: Gamma
Answer: C: Gamma 
Explanation: Ans. (c) GammaRef.: Essentials of radiological Science 2nd ed. /10* Maximum penetrating is gamma rays, therefore least dangerous. Hence gamma camera is used therapeutically for myocardial perfusion imaging.* Least penetrating is alpha rays, therefore most dangerous