What do two solid yellow lines on a two-lane road signify?

Answer: B — No passing in either direction

Two solid yellow lines on a two-lane road indicate that passing is not allowed in either direction. This traffic marking is designed to enhance safety by preventing drivers from attempting to overtake other vehicles where visibility may be limited or where it is deemed unsafe to do so. It emphasizes that all vehicles must remain in their lanes, which is crucial for minimizing the risk of head-on collisions and ensuring smooth traffic flow. The presence of two solid lines serves as a clear and authoritative message to drivers that maintaining their position in the lane is essential for road safety.