Which of the Following Statements Is True Concerning Fluoridation of Water

Which of the following statements is true concerning fluoridation of water in the United States?

A) More than 75% of the U.S. population is served by community water systems with optimally fluoridated water.
B) Twenty-five percent of people in the United States receive water with sufficient naturally occurring fluoride concentrations.
C) More than 50% of the U.S. population does not have access to optimally fluoridated water.
D) The percentage of the population served by community water systems receiving optimally fluoridated water varies substantially by state.