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 minor connector for a mandibular distal extension base should extend posteriorly about _____. \nSelect and explain. \nA. Two-third the length of the edentulous ridge, B. Half the length of the edentulous ridge, C. One-third the length of the edentulous ridge, D. As long as possible', 'role': 'user'}, {'content': 'Answer: A \nExplanation: The minor connector for the mandibular distal extension base should extend posteriorly about two thirds the length of the edentulous ridge; this adds strength to the denture base.', 'role': 'assistant'}]