What does a yellow diamond-shaped sign indicate?

Answer: B — Warning of a potential hazard

A yellow diamond-shaped sign serves the important function of warning drivers about potential hazards or changes in the road conditions ahead. These signs are designed to alert motorists to various situations that may require increased caution, such as sharp turns, pedestrian crossings, or other situations that could affect driving safety. The bright yellow color and diamond shape are standardized to ensure high visibility and quick recognition, making it easier for drivers to react appropriately to unexpected conditions. This is why the correct answer highlights the warning aspect of these signs, as they play a crucial role in maintaining roadway safety by warning drivers of impending changes in their driving environment.