What action does a "speed limit" sign indicate?

Answer: B — Maximum allowable speed

A "speed limit" sign indicates the maximum allowable speed that vehicles can legally travel on that particular stretch of roadway under ideal conditions. This regulation is established to promote safety and ensure the smooth flow of traffic. Drivers must not exceed this speed, as doing so can result in legal penalties and increased risks of accidents. While there are other signs that provide recommendations or guidelines regarding speed based on conditions or safety, a speed limit sign is specifically about the upper limit of safe driving speed that has been determined for that road segment. Therefore, understanding the primary role of speed limit signs in managing roadway safety is essential for all drivers.