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': "Kim's classification type IV is \nSelect and explain. \nA. Incomplete isthmus between two canals, B. Well defined complete isthmus between two canals, C. 3 or more canals with complete or incomplete isthmus, D. 3 or more canals without any visible connections", 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]