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
RPI stands for: 
Select and explain. 
A. Occlusal rest, proximal plate, I bar, B. Cingulum rest, proximal plate, I bar, C. Rest, proximal guide plane, I bar, D. Rest, proximal plate, indirect retainer
A: Occlusal rest, proximal plate, I bar
Answer: A: Occlusal rest, proximal plate, I bar 
Explanation: None