What must a driver do before entering a roundabout?

Before entering a roundabout, a driver must yield to pedestrians and bicycles in the crosswalk. This is crucial for ensuring the safety of those crossing the road, as pedestrians and cyclists have the right of way in these situations. When approaching a roundabout, drivers should be vigilant and aware of their surroundings, making sure to allow these vulnerable road users to cross safely.

In contrast, the other options may not align with the proper protocol for navigating roundabouts. Speeding up to merge can increase the risk of accidents as it ignores the need to yield to traffic already in the roundabout. Stopping and looking both ways might be necessary at some intersections, but roundabouts are designed to keep traffic moving, and stopping could disrupt the flow and lead to unsafe conditions. Signaling left before entering might be misleading, as left turns are generally made after entering the roundabout, not before. Overall, yielding to pedestrians and bicycles is the priority to maintain safety when approaching roundabouts.