What is the speed limit in a residential area unless posted otherwise?

Answer: B — 25 mph

In residential areas, the standard speed limit is set at 25 mph unless otherwise posted. This speed limit is established to ensure the safety of residents, particularly children and pedestrians who may be walking in these areas. By keeping the limit at 25 mph, it balances the need for traffic flow with the necessity of maintaining a safe environment for those living nearby. Faster speeds can lead to more severe accidents and increased risks to pedestrians, especially in neighborhoods where children play. The presence of speed limit signs is also meant to remind drivers of the speed that is considered safe in these environments.