You are writing an article about the importance of teeth-brushing. Your readers will be 8-12 year-olds. Which of these would make the most appropriate opening sentence?
A) Some people wonder if fluoride is good for you or not.
B) Teeth-brushing is a relatively recent phenomenon in history.
C) Science had made many advances in the area of maintaining teeth cleanliness and health.
D) Brushing your teeth is very important, not only to prevent cavities, but also to fight gum disease.