Which of the following is the most appropriate unit to describe the rate at which people are entering a theme park? . a. hours per person, because the dependent quantity is the hours. b. hours per person, because the dependent quantity is the people. c. people per hour, because the dependent quantity is the hours. d. people per hour, because the dependent quantity is the people.

Counting hours per person just wouldn't make sense. So you can immediately cross out choices A and B. Now the only choices to choose from is C or D, and now, we only have to decide if the dependent quantity is either the hours or the number of people. The answer here would be D, since time cannot be a dependent quantity. No matter how many people pass by, time will always go on. Therefore, the dependent quantity is the amount of people.