What should drivers do when they encounter a roundabout?

Answer: B — Yield to traffic already in the roundabout

Yielding to traffic already in the roundabout is essential for safe navigation. Roundabouts are designed to facilitate a continuous flow of vehicles while reducing the likelihood of collisions. When a driver approaches a roundabout, they must account for vehicles that are already circulating within it. By yielding, drivers allow those already in the roundabout to continue without interruption, which helps maintain traffic flow and reduces congestion. Entering a roundabout without yielding can lead to accidents, as it might force circulating vehicles to suddenly alter their speed or direction to avoid a collision. Therefore, understanding the importance of yielding ensures that all drivers can use roundabouts safely and effectively, minimizing potential hazards on the road.