Which type of line allows pedestrians to cross only when the traffic light is red?

The correct choice is the type of line that indicates to pedestrians they may cross only when the traffic signal shows red for vehicles. In a signalized pedestrian lane, the coordination of traffic lights is specifically designed to control pedestrian crossing times based on the signals. When the traffic light turns red for vehicles, it signals that it is safe for pedestrians to proceed across the street. This arrangement ensures that pedestrians only cross when it is designated safe by the traffic signals, enhancing their safety on the road.

Other options, such as non-signalized lanes, do not have organized traffic signals managing pedestrian crossings; thus, pedestrians may cross at any time, usually depending on their own judgment of traffic conditions. Crosswalks, while also designated areas for pedestrians, do not inherently imply that there are signals for stopping traffic, as they can exist at both signalized and non-signalized locations. Loading zones are designated areas where vehicles can load or unload but do not have any provisions specifically for pedestrian crossings.