Arun is driving on a long road trip. He wrote an equation to represent how many gallons of gas he has left in his tank, g, equals 14 minus 0.5h, where g represents the number of gallons and h represents time in hours. What could the number 14 represent in the equation?

a) How long it takes Arun to run out of gas.
b) How quickly the car uses gas, in gallons per hour.
c) The number of gallons of gas at time h equals 0h=0.
d) The number of gallons in the tank when the trip ends.