What does a solid yellow line mean?

Answer: B — Passing is not allowed

A solid yellow line signifies that passing is not allowed. This means drivers are prohibited from crossing the line to overtake another vehicle. The yellow line acts as a clear visual cue to indicate that the road conditions, visibility, or proximity to oncoming traffic make passing unsafe. It is designed to help prevent accidents by discouraging maneuvers that could lead to dangerous situations, especially in areas where visibility is limited or on roads with higher traffic volumes. In contrast, a dashed or broken yellow line would indicate that passing is permissible when it is safe to do so. Other options, such as indicating a pedestrian crossing or being exclusively for bike lanes, are not applicable to a solid yellow line, as its primary function is to regulate vehicle passing.