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': 'The mandibular distal extension RPD extends up to \nSelect and explain. \nA. Full length of Retromolar pad, B. Anterior one third length of retromolar pad, C. Anterior 2/3 rd of Retromolar pad, D. None of above', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]