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 et al classification system deals with: \nSelect and explain. \nA. Apical constriction, B. Apical foramen, C. Isthmus, D. No. of canals', 'role': 'user'}, {'content': 'Answer: C \nExplanation: According to Kim et al Classification; there are 5 types\n\nType I incomplete isthmus between 2 canals.\nType II well defined, complete isthmus between 2 canals.\nType III very short but complete isthmus between 2 canals.\nType IV 3 or more canals with the complete or incomplete isthmus.\nType V 3 or\xa0more canals without any visible connection.', 'role': 'assistant'}]