PLEASE HELP A ranger at a local park wants to know which type of trees the park's visitors would like to have planted in the park. She conducts a survey. Which of these methods will produce the most representative sample of the people who visit the park?
A. The ranger surveys all the children who enter the park
B. The ranger surveys all the people who come to the park to watch birds
C. The ranger randomly selects days of the week and surveys each person who enters the park on those days
D. The ranger surveys people who camp overnight in the park