What does a single solid white line across a road at an intersection indicate?

A single solid white line across a road at an intersection serves as a clear indicator for drivers. Specifically, it signifies that you need to stop within a certain distance—typically indicated by the line itself—when you encounter a stop sign or a traffic signal. This line guides drivers to a designated stopping point, ensuring that they come to a complete stop before proceeding through the intersection. It enhances safety by allowing for better visibility of oncoming traffic and helps regulate the flow of vehicles at busy intersections.

In the context of the other options, they do not accurately reflect the purpose of the solid white line. The line is not used to communicate a speed limit, allow for proceeding without stopping, or yielding to cross traffic. Each of those scenarios involves different road markings or signs.