Which type of sign is used to regulate traffic speed limits?

Answer: B — Rectangular-shaped sign

The rectangular-shaped sign is used to regulate traffic speed limits because this shape is commonly associated with regulatory signs that provide essential information about laws and regulations that drivers must follow. These signs are designed to be clear and easily recognizable, ensuring that drivers can quickly understand the rules of the road. Speed limit signs are typically white with black text, conveying the maximum speed allowed in a particular area, helping to promote safety by encouraging drivers to obey the posted limits. This shape effectively communicates regulatory information, differentiating it from warning signs, which are often diamond-shaped, and other types of signs that serve different purposes.