Karl set out to Alaska in his truck.

The amount of fuel remaining in the truck’s tank (in liters) as a function of distance driven (in kilometers) is graphed. (Graph attached below).

How fast did the truck consume it’s fuel?

A) 60 liters per kilometer

B) 40 liters per kilometer

C) 0.4 liters per kilometer

D) 0.6 liters per kilometer

Any help is appreciated. :)