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': 'Most recent form of MTA used as an intracanal irrigant? \nSelect and explain. \nA. MTA-A, B. MTA-C, C. MTA-D, D. MTA-E', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]