Question

to avoid accidents, drivers should communicate with each other by: signaling when changing lanes/direction, slowing down or stopping using their horns in emergencies and when really necessary using emergency flashers/flares/signs as needed all of the above

Explanation:

To avoid accidents, drivers use multiple communication methods: signaling for lane changes/direction, speed changes; horns in emergencies; emergency flashers/flares/signs as needed. So all these methods are valid, making "All of the above" the correct choice.

Answer:

D. All of the above (assuming the options are labeled A, B, C, D with D being "All of the above" for the four options: Signaling..., Using their horns..., Using emergency..., All of the above)