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': 'In irreversible pulpitis intrapulpal pressure becomes: \nSelect and explain. \nA. 10mmof Hg., B. 20mm of Hg., C. 25mm of Hg., D. 40mm of Hg.', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Normal intrapulpal pressure is 10mm of Hg.', 'role': 'assistant'}]