Well, if Pablo gets 1 free minute for every 5 paid,
then he would get 8 free minutes for every 40 paid,
Sam is getting only 25 paid minutes for every 8 free ones
The initial deceleration is 4 m/s^2, so this means that considering the first line segment,
.
The total distance traveled is 4 km, which is equal to 4000 meters. This is equal to the area under the graph, so
.

C is the rigth answer because all the other three has two x values in common. :)