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
Which of the following has mot penetrating power ? 
Select and explain. 
A. α – particle, B. β – particle, C. γ – radiation, D. Electron beam
C: γ – radiation
Answer: C: γ – radiation 
Explanation: Penetration Power
Maximum : Gamma - rays (1000 times of arays)
Minimum : Alpha rays