Braking efficiency increases, among other circumstances, when...
A)The vehicle's mass is greater, since the greater the mass, the shorter the braking distance.
B)The clutch pedal is pressed at the same time as the brake pedal.
C)The adhesion of the tyres to the ground is greater.Correct
# Explanation
Braking efficiency depends mainly on the **adhesion of the tyres to the road surface**. The greater this adhesion, the better the vehicle's ability to stop, regardless of its mass. Conversely, a greater vehicle mass increases the braking distance, and pressing the clutch reduces the engine's braking power.