What does a red X indicate on a traffic sign?

Answer: B — Lane is closed

A red X displayed on a traffic sign is a clear indication that a lane is closed to traffic. This symbol is universally recognized as a signal for drivers to avoid that particular lane due to potential hazards or restrictions, such as road work, accidents, or other obstructions that make it unsafe for vehicles to proceed. The use of a red X emphasizes the need for caution and compliance with traffic management systems, ensuring safety for both drivers and any workers or equipment that may be present in the closed lane. The presence of this signal often means that drivers should change lanes or prepare to stop, as entering the lane marked by a red X could lead to accidents or further complicate traffic conditions.