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: Unknown
About Bragg peak effect of protons all are true except: 
Select and explain. 
A. Electromagnetic radiation, B. Produce ionization in biological system, C. The dose of a single beam is two to four times greater than the path dose, D. Beam therapy for AV malformation of the brain
A: Electromagnetic radiation
Answer: A: Electromagnetic radiation 
Explanation: Ref. Grainger and Allison's Diagnostic Radiology. Page. 30
 
Bragg Peak

The Bragg peak is a pronounced peak on the Bragg curve which plots the energy loss of ionizing radiation during its travel through matter.
For protons, α-rays, and other ion rays, the peak occurs immediately before the particles come to rest