To drive preventively on an icy road surface, you must...

A)take special care during the day.
B)reduce speed and use low gears.
C)reduce speed and use high gears.Correct
Adapting your driving to adverse environmental conditions is also vitally important in order to drive preventively and avoid accidents.
If we encounter ice on the road, the advisable course of action is to reduce speed, drive in high gears and brake very gently.
On ice, grip is practically zero. The wheels do not respond to steering wheel input (the steering feels very light) and the braking distance can increase up to 10 times.
The braking distance is the distance the vehicle travels from the moment the brakes are applied until the vehicle comes to a stop.