Where is parking not allowed?

Answer: A — Within 15 feet of a crosswalk

Parking is not allowed within 15 feet of a crosswalk because this distance ensures that pedestrians can safely enter and exit crosswalks without obstruction. It is essential for maintaining visibility for both pedestrians and drivers, as vehicles parked too close to crosswalks can block sightlines and pose a danger to those crossing the street. Adequate space around crosswalks not only enhances safety but also allows for smoother traffic flow, as drivers can see pedestrians approaching the crosswalk with sufficient time to stop. The other options focus on different spacing regulations that may apply in specific contexts, but the regulation about crosswalks is critical for pedestrian safety and is strictly enforced to minimize the risk of accidents. It highlights the importance of being mindful of the area around pedestrian pathways while driving or parking.