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
Which is the first study on water fluoridation? 
Select and explain. 
A. Grand rapids (Michigan) & Muskegon, B. Newberg & Kingston, C. Brantferd & Sarnia, D. Evanston & Park
A: Grand rapids (Michigan) & Muskegon
Answer: A: Grand rapids (Michigan) & Muskegon 
Explanation: None