When Lana rides her bike from her house to school at a rate of r miles per hour, the trip takes her m minutes. Which statement describes the relationship between r and m? A. r is the dependent variable because r affects the number of minutes it takes Lana to ride to school.
B. r is the dependent variable because m affects how fast she rides her bike.
C. r is the independent variable because r affects the number of minutes it takes Lana to ride to school.
D. r is the independent variable because m affects how fast she rides her bike.