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 direct retainer is indicated in the case of an isolated, mesially inclined molar? \nSelect and explain. \nA. 1/2 and 1/2 clasp, B. Ring clasp, C. Bar clasp, D. C-clasp', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]