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
Treatment time for topical fluoride application on deciduous teeth is 
Select and explain. 
A. 1 minute, B. 2 minute, C. 3 minute, D. 4 minute
D: 4 minute
Answer: D: 4 minute 
Explanation: 4-minute treatment time has been typically recommended for professionally applied topical fluoride solutions, gels, or foams.