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': 'The most important diagnostic test to differentiate between an Acute periapical Abscess and a Phoenix Abscess is \nSelect and explain. \nA. Pulp testing, B. Radiographs, C. History, D. Percussion', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]