When approaching a stale green light, a cautious driver should assume:

Answer: B — It may soon turn yellow

When approaching a stale green light, a cautious driver should assume that it may soon turn yellow. A stale green light is one that has been green for some time, and while it is still in the green phase, there is a possibility that it could change to yellow. This indicates that the driver should prepare to stop rather than assume that they can continue through the intersection safely. By anticipating the change, the driver can make a more informed decision, whether to slow down and stop if necessary or proceed with caution if the light remains green. This approach promotes safety and reduces the risk of running a red light or causing an accident.