What does a solid yellow line indicate?

Answer: B — Passing is not allowed

A solid yellow line on the road signifies that passing is not allowed. This marking is used to indicate that it is unsafe to overtake another vehicle due to various factors such as visibility, road conditions, or the potential presence of oncoming traffic. Drivers should remain in their lanes when a solid yellow line is present, as crossing this line could lead to dangerous situations and contribute to accidents. The other options describe lanes intended for different uses or situations, but a solid yellow line specifically is concerned with maintaining safety on the road by restricting passing in the adjacent lanes. Understanding this marking is crucial for drivers to follow traffic laws and promote safe driving practices.