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: Surgery
Which of the following is used to measure pain intensity 
Select and explain. 
A. Visual analog scale, B. Visual anaesthesia score, C. Verifiable assessment of soreness, D. Visual assessment of soreness
A: Visual analog scale
Answer: A: Visual analog scale 
Explanation: None