What must you do before merging onto an express highway or freeway?

Answer: B — Move to the acceleration lane

Before merging onto an express highway or freeway, it is essential to move to the acceleration lane. The acceleration lane allows drivers to increase their speed to match the flow of traffic on the highway. This smooth transition is crucial for maintaining safety for both the merging vehicle and other drivers already on the expressway. When you enter the acceleration lane, you should check your mirrors and blind spots, use your turn signals to indicate your intention to merge, and then adjust your speed as needed to merge safely into the traffic. This approach facilitates a smoother merging process and reduces the risk of collisions. The other options involve actions that would either disrupt the flow of traffic or not provide safe merging conditions. For instance, stopping and yielding could cause a backup and increase the likelihood of accidents, while signaling for an extended period without preparing to merge does not contribute to safe entry onto the freeway. Similarly, completely slowing down would not help in merging effectively with faster-moving traffic.