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': 'Vitality test has to be done over a PFM crown, which is the best test to be done in order to check the vitality: \nSelect and explain. \nA. EPT., B. Cold test., C. Cavity test., D. All of the above.', 'role': 'user'}, {'content': 'Answer: B \nExplanation: For PFM → EPT is contraindicated, instead cold test With CO2 snow/“TRIGIDENT “is a\xa0 test of Choice. (Temperature of dry ice/CO2 snow is–78ºC) .', 'role': 'assistant'}]