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
The rate of mixed whole stimulated saliva increases with age in which of the following  age group (according to Crossner) 
Select and explain. 
A. 1-2 year of Age, B. 5-15 year of Age, C. 3-4 year of  Age, D. Above 15 years
B: 5-15 year of Age
Answer: B: 5-15 year of Age 
Explanation: Crossner reported that in children from 5 to 15 years of age, the rate of mixed whole stimulated saliva increases with age, and boys have consistently higher rates than girls.  Saliva substitutes, as well as fluoride and chlorhexidine rinses, are reported to enhance remineralization and promote resistance to demineralization of tooth surfaces, and may help prevent radiation-induced caries.