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
The darkening of radiograph X-ray depends on all except: 
Select and explain. 
A. Thickness of object, B. Quality and quantity of X-rays, C. Angulation cone, D. Velocity of electron emitted from cathode
C: Angulation cone
Answer: C: Angulation cone 
Explanation: None