What does a Speed Limit sign indicate?

Answer: A — white rectangle that says Speed Limit 65

A Speed Limit sign is specifically designed to convey the maximum legal speed at which a vehicle may travel on that stretch of road. The description provided in the first option, which mentions a white rectangle stating "Speed Limit 65," accurately reflects the standard appearance of these signs in the United States, including Arizona. These signs are typically rectangular and feature a clear and easily readable format that includes the maximum speed limit in bold numbers. The color and shape of the sign are important because the white background is used universally for regulatory signs, indicating that adhering to the posted limit is legally required. This helps drivers quickly recognize and understand their obligations while driving. The numeric value indicates the specific speed limit, ensuring drivers are aware of the maximum speed they should not exceed under normal driving conditions. The other options do not accurately describe the typical Speed Limit sign. For instance, a square sign with a numeric value might indicate something else entirely, while a red circle usually signifies prohibition, such as "Do Not Enter" or "Speed Limit Violated." Lastly, a blue rectangular sign often conveys information about services or directions rather than speed regulations.