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: \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: Kim\xa0et\xa0al\xa0Classification\nRoot Apex cross-section\nNarrow\xa0ribbon-shaped\xa0connection that contains pulp or pulpally derived tissue :\xa0ISTHMUS\nAccording to Kim et al classification;\xa0there are 5 types:\n\nType I :\xa0Incomplete\xa0isthmus between 2 canals.\nType II : Well defined,\xa0complete isthmus between 2 canals.\nType III :\xa0Very short but complete\xa0isthmus between 2 canals.\nType IV :\xa03 or more\xa0canals\xa0with the complete or incomplete isthmus.\nType V :\xa03 or more\xa0canals\xa0without any visible\xa0connection.', 'role': 'assistant'}]