What signals indicate that the bus operator is preparing to make a turn?

Activating turn signals and checking mirrors is the proper procedure that indicates a bus operator is preparing to make a turn. Turn signals are essential for communicating the operator's intention to other drivers and pedestrians, helping to enhance safety by providing clear indications of upcoming maneuvers. Additionally, checking mirrors ensures that the operator is aware of the surroundings, including other vehicles and pedestrians, before making the turn. This combination of signaling and situational awareness is crucial in preventing accidents and ensuring smooth traffic flow.

While other options involve actions that may be relevant in different contexts of driving, they do not specifically or effectively communicate the preparation for a turn. For example, using the horn and slowing down could be appropriate in various situations but doesn’t provide a clear indication of an imminent turn. Switching headlights or flashing brake lights are not standard practices for indicating a turn and could instead confuse other road users. Lastly, turning on emergency lights is reserved for emergencies and does not signal a turn, which is why the correct choice directly addresses the specific requirement for indicating a turn.