The question is on a test I have to do today! pls help me!

10. Which situation can be modeled by the equation y=m x+b ?

A. The number of butterflies (y) in a population doubles every month (x).

B. The time (y) it takes a car to travel 100 miles depends on the speed (x) of the car.

C. The volume (y) of a cylindrical tank with a height of 2 feet depends on the radius (x) of the tank.

D. The total income (y) of a worker who earns 8 dollars per hour depends on the number of hours (x) worked.