Which car has the greatest efficiency?
A: a 900 kg car that travels 15 km per liter of fuel
B: a 1,200 kg car that travels 15 km per liter of fuel
C: a 900 kg car that travels 20 km per liter of fuel
D: a 1,200 kg cae that travels 20 km per liter of fuel
C: a 900 kg car that travels 20 km per liter of fuel.
This car has the greatest efficiency as it can travel the farthest distance on the least amount of fuel.