A skateboarder is practicing in the city park. He is skating up and down the steepest straight-line ramp. If the highest point on the ramp is 30 feet above the ground and the horizontal distance from the base of the ramp to a point directly beneath the upper end is 500 feet, what is the slope of the ramp?

A)500/30
B)50/3
C)3/50
D) None of these