Answer:
Part 1: B. to point out the benefits of adding fluoride to city water supplies
Part 2: B. Since 1945, the country's dental health has gotten much better, and we are also more aware of how important good dental care is.
Step-by-step explanation:
One of the benefits of adding fluoride to water supplies is better dental health, aka stronger teeth.
In addition, the answer to part 2 shows that adding fluoride to water supplies has been proven efficient for over 7 decades (since 1945), which shows that fluoride with water is a healthy combination for us to use.
Option D in part 2 only states the experts' opinions on fluoride being added to city water, not the actual benefits of fluoride being added to city water.