What does an officer swinging a red or yellow light indicate?

A)That we should drive with caution.
B)That there is a hazard.
C)It requires all road users towards whom the light is directed to stop.Correct
The red or yellow light requires road users towards whom the light is directed to stop.
Do not confuse it with the up-and-down arm movement which means that we should slow down.
Do not confuse it with the up-and-down arm movement which means that we should slow down.