What does a solid red traffic light mean?

Answer: B — Stop and wait until the light turns green

A solid red traffic light indicates that drivers must stop completely and remain stopped until the light changes to green. This rule is in place to ensure safety at intersections, allowing cross traffic to proceed and preventing accidents. It’s important to wait behind the stop line or crosswalk until the signal indicates that it’s safe to move. The other options do not accurately reflect the requirement associated with a solid red light. Although slowing down and preparing to stop is a prudent practice when approaching a red light, the definitive action required is a complete stop. Proceeding with caution implies that one might go through the intersection despite the light, which would be unsafe and against traffic regulations. Noting that one should stop only if there are vehicles present could lead to confusion and dangerous situations, as the law applies regardless of other traffic.