The equation d=40t represents the distance a car travels in miles (d) after traveling for t hours. What is the slope, and what does it represent?

A) Slope = 40; Represents the initial distance
B) Slope = 40; Represents the speed of the car
C) Slope = 1/40; Represents the time taken per mile
D) Slope = 1/40; Represents the velocity of the car