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: Dental
Factor constituting the quality and quantity of pain: 
Select and explain. 
A. Spontaneity, intensity, duration, B. Character, severity, C. History, location, diagnosis, D. Stimulus, severity
A: Spontaneity, intensity, duration
Answer: A: Spontaneity, intensity, duration 
Explanation: The three important factors constituting the quality and quantity of pain are its spontaneity, intensity, and duration