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
Best heat test agent for pulp testing: 
Select and explain. 
A. GP sticks., B. Rubber wheel., C. Barlew disk., D. Rotation friction heat.
A: GP sticks.
Answer: A: GP sticks. 
Explanation: None