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
[{'content': 'Which of the following is the current concept of clasp design of bar clasp? \nSelect and explain. \nA. I bar clasp, B. RPI system, C. RPA system, D. RPM system', 'role': 'user'}, {'content': 'Answer: B \nExplanation: The RPI is a current concept of bar clasp design, and refers to the rest, proximal plate, and I bar component parts of the clasp assembly.', 'role': 'assistant'}]