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
First systemic fluoride electrode is given by? 
Select and explain. 
A. Shyler and Armstrong, B. Frant and Ross 1966, C. Estrond 1970, D. Duck and Morgan 1970
B: Frant and Ross 1966
Answer: B: Frant and Ross 1966 
Explanation: None