How do you know if a roundabout is approaching?

Answer: C — Look for the circular warning sign

The correct answer highlights the significance of the circular warning sign, which is specifically designed to alert drivers to the presence of a roundabout ahead. This sign typically features a circular shape with arrows indicating the direction of traffic flow around the roundabout, making it a recognizable and clear signal for drivers. Recognizing this sign allows drivers to prepare for the change in traffic pattern that roundabouts introduce, such as yielding to vehicles already in the roundabout and adjusting their speed accordingly. It is a proactive way to ensure safety and smooth navigation through intersections where roundabouts are present. Other choices may contribute to situational awareness but do not provide the same definitive indication of an approaching roundabout. Traffic lights are generally present at intersections but are not typically used with roundabouts, while honking may occur in various traffic situations and does not specifically signal a roundabout. Road markings can also indicate certain road conditions but are not as clear as a dedicated warning sign for roundabouts.