What does a yellow traffic signal indicate?

Answer: C — Vehicles should prepare to stop; light is about to turn red

A yellow traffic signal serves as a warning that the light is about to change to red, advising drivers to prepare to stop. This indication is crucial for maintaining safety at intersections, as it allows vehicles that are already in the intersection to clear it safely while informing those approaching that they need to slow down and halt if they haven't yet entered the intersection. Understanding this function helps prevent accidents by ensuring that drivers know the signal's purpose is to prompt readiness to stop. When the light changes from green to yellow, it's a critical transition indicating that drivers need to act accordingly to avoid running a red light, which can lead to collisions.