You are forced to stop on the side of a one-way or divided highway that is straight and level. Where should you place the reflective triangles?

a) 10 feet, 100 feet, and 200 feet behind the vehicle
b) 50 feet, 100 feet, and 150 feet behind the vehicle
c) 100 feet, 200 feet, and 300 feet behind the vehicle
d) 50 feet, 150 feet, and 250 feet behind the vehicle