Dan’s football team brings a 5-gallon cooler of Thirstade to every game so players can stay hydrated throughout the game. The amount of Thirstade in the cooler can be modeled by the equation y=5−0.2x, where y is the amount of Thirstade in the cooler in gallons, and x is the number of players who have taken a drink of Thirstade. Which best describes the amount, in gallons, of Thirstade that is in the cooler at any time, x?
A. The amount of Thirstade in the cooler decreases at a constant rate.
B. The amount of Thirstade in the cooler increases at a constant rate.
C. The amount of Thirstade in the cooler decreases at an exponential rate.
D. The amount of Thirstade in the cooler increases at an exponential rate.