What does a yellow diamond-shaped sign indicate?

Answer: B — Warning

A yellow diamond-shaped sign is a standardized symbol used to indicate warnings to drivers on the road. These signs are designed to alert drivers to potential hazards or changes in road conditions ahead, such as sharp turns, pedestrian crossings, animal crossings, or other cautionary situations. The yellow color enhances visibility and reinforces the need for attention and caution. In contrast, other sign shapes and colors are used for different purposes. For example, speed limit signs typically use rectangular shapes with black numbers on a white background. Signs providing information about upcoming services, such as gas stations or rest areas, are usually blue or green and have a different design. Construction zone signs are often orange and take on a different shape, typically a diamond or rectangle, to indicate construction hazards specifically. The yellow diamond shape uniquely conveys a warning message, which is its primary purpose.