What is the speed limit in urban districts unless otherwise posted?

Answer: B — 30 miles per hour

The speed limit in urban districts is set to 30 miles per hour unless otherwise posted. This standard is established to ensure safety within areas that include higher pedestrian activity and more street traffic, such as residential neighborhoods and business districts. A speed limit of 30 mph strikes a balance between allowing for traffic flow and ensuring that drivers react appropriately to potential hazards, like pedestrians and cyclists. Other choices do not represent the standard speed in urban areas, as 25 mph is often used in specific high pedestrian areas, and higher limits like 35 mph or 40 mph may apply to different types of roadways outside dense urban settings. Understanding these limits is crucial for safe driving practices and compliance with local traffic laws.