What does a yellow traffic light indicate?

Answer: D — Traffic is about to change to red

A yellow traffic light indicates that the signal is about to change to red, warning drivers to prepare to stop. It serves as a cautionary alert that the current traffic light is transitioning, giving drivers an opportunity to clear the intersection if they are already in it or to slow down and stop if they have not yet crossed. This understanding is essential for safe driving; recognizing that a yellow light does not mean to enter the intersection hastily, but rather to be prepared for the impending red light helps prevent accidents. Drivers should always treat a yellow light as a signal to assess their position and act accordingly, either by slowing to a halt or proceeding with care if they can safely do so.