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': 'First systemic fluoride electrode is given by? \nSelect and explain. \nA. Shyler and Armstrong, B. Frant and Ross 1966, C. Estrond 1970, D. Duck and Morgan 1970', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]