When should a moped rider use their horn?

Using the horn as a moped rider is primarily about enhancing safety and communication with others on the road. It's important to utilize the horn to alert drivers, pedestrians, and other road users of your presence or to warn them of potential hazards. This could include situations where a vehicle is about to make an unexpected move or when visibility is reduced.

The option that focuses on alerting others when necessary for safety encapsulates this purpose perfectly. It emphasizes the need for awareness and caution, ensuring that moped riders can prevent accidents by effectively communicating their intentions or existence to others around them.

Other choices suggest scenarios like passing another vehicle, riding at night, or being in a parking lot, which do not encompass the broader and more critical aspect of using the horn for safety reasons in a variety of situations. Thus, the guidance to use a horn whenever needed for safety is the most comprehensive and responsible approach for moped riders.