What is the purpose of merging lanes when traffic is congested?

Answer: A — To prevent slow-moving vehicles from blocking the right lane

When traffic is congested, merging lanes allows for slower-moving vehicles to move out of the way and prevent them from blocking the faster-moving vehicles in the right lane. This helps maintain a steady flow of traffic and prevent accidents. The other options are incorrect because merging lanes is not meant to force vehicles to slow down, create more space on the highway, or give preference to drivers with fast vehicles. The main purpose is to maintain the flow of traffic and prevent disruptions caused by slower-moving vehicles.