What does a solid yellow line mean?

Answer: A — No passing; it indicates the edge of the lane

A solid yellow line indicates that no passing is allowed. It is used to mark the left edge of the lane on divided highways and to separate traffic moving in opposite directions on two-way roads. The solid line signifies that it is unsafe to cross over to the other lane to pass another vehicle. While other options reference lane separation and warnings, a solid yellow line specifically communicates to drivers that they should remain in their lane and not attempt to overtake another vehicle, emphasizing safety on the road. A solid yellow line serves as a clear regulatory measure to promote responsible driving behavior.