When may you use your horn and flashing headlights?

Answer: A — To alert others of your presence. The horn should only be used to warn for danger

Using your horn and flashing headlights should only be done when necessary, such as to alert others of your presence in a potentially dangerous situation. Using them for any other reason, such as making a statement or responding to aggressive drivers, may cause unnecessary noise and distractions on the road. Additionally, using them in non-residential areas where there are fewer drivers and pedestrians may not be necessary. So, option A is the only appropriate reason to use your horn and flashing headlights.