Which of the following is a benefit of water fluoridation?

The benefit of water fluoridation that stands out is the reduction of childhood caries. Water fluoridation has been shown to significantly lower the incidence of dental caries (cavities) in children, as fluoride helps strengthen tooth enamel and makes it more resistant to acid attacks from plaque bacteria and sugars in the mouth. The constant, low-level exposure to fluoride through drinking water contributes to the overall health of teeth, leading to fewer cavities, which is especially important during the developmental years of childhood. Studies have consistently supported this finding, demonstrating that communities with fluoridated water have lower rates of tooth decay compared to those without.

The other choices do not reflect the positive outcomes associated with water fluoridation. Increasing dental decay, higher dental treatment costs, and staining of teeth don't represent the intended benefits of fluoridation; in fact, they are contrary to the evidence that supports the effectiveness of fluoride in preventing dental diseases.