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
Maximum penetration is seen with: 
Select and explain. 
A. cc paicles, B. 13 paicles, C. y paicles, D. Electron beam
C: y paicles
Answer: C: y paicles 
Explanation: Ans. y paicles