Which circumstance prohibits stopping and parking along the roadway?

Stopping and parking along a roadway is prohibited within 5 meters of a fire hydrant to ensure that emergency vehicles can access water in case of a fire. This regulation is crucial for public safety; if a fire hydrant is blocked by a parked vehicle, firefighters may face delays in obtaining the necessary water to combat a fire, potentially putting lives and property at risk.

Other factors, like the time of day or specific locations such as cafés or residential neighborhoods, may have their own parking regulations, but the critical issue with fire hydrants is universally recognized. Fire safety laws emphasize keeping fire hydrants clear to facilitate immediate access during emergencies, making option C the correct answer.