How should we act to save fuel?

A)We will always turn off the engine, both in traffic jams and at traffic lights and intersections where we must yield.
B)We will drive in the shortest gear and accelerate smoothly.
C)We will drive smoothly, without sudden braking or acceleration.Correct
Proper gear regulation is one of the key aspects of efficient driving. At a given speed, the longer (higher) the gear engaged and the lower the vehicle's revolutions, the less fuel we will be using. Therefore, to drive efficiently, we will use the longest gear that allows us to travel at the desired speed, driving smoothly, without sudden acceleration and braking.