The headlights are shining on a truck travelling at 100 km/h. The speed of the light from the headlights relative to the road will be:

Ac

Bc + 100 km/h

Cc – 100 km/h

Ddepends on the temperature, but faster than the speed if the truck was not moving.

Efaster than if the truck was not moving, but impossible to calculate with the given information