When should a driver use their turn signals?

Using turn signals is an essential aspect of safe driving as it communicates a driver's intentions to other road users. The correct context for signaling occurs whenever a driver is changing lanes, making a turn, or merging into traffic. This practice enhances safety by alerting other drivers and pedestrians about the driver's maneuvers, allowing them to respond accordingly.

For instance, signaling while changing lanes informs fellow motorists of your intention to move into their lane, thereby reducing the chances of collisions. Similarly, signaling when turning lets pedestrians and other vehicles know where you plan to go, promoting smoother traffic flow and safety on the road.

The other options do not encompass the complete scope of situations where turn signals should be used. Stopping at a red light does not require signaling since the vehicle is not changing position, while signaling only in residential areas or when requested by another driver limits the safety practice to unrealistic or inappropriate situations. Thus, option B comprehensively captures the necessary scenarios for using turn signals and is fundamental for responsible driving behavior.