Which of the following situations would best be modeled by an exponential function? A. The area of a square given its side length.
B. The amount of money in Mary's savings account after x years, if the account earns 8% annual interest.
C. The relationship between time and distance, if George drove a constant rate of 70 mph to his grandmother's house when he went to visit over the summer.
D. The number of vans the math club needs to take on a trip based on x number of students, where each van can take up to 15 students.