How are restricted areas marked at the airfield?

Answer: B — A red restricted area boundary marking and a sign

Restricted areas at an airfield are specifically marked to ensure safety and proper operations. The use of a red restricted area boundary marking, along with signage, is a standardized method that clearly indicates that the area is off-limits to unauthorized personnel and vehicles. This visual cue is crucial in maintaining order at the airfield, as it helps prevent accidental incursions into potentially hazardous areas where flight operations or ground activities may pose risks. The red color is universally recognized as a warning signal, effectively capturing attention and emphasizing the importance of adhering to restrictions in these zones. The accompanying signs provide additional information and instructions, further ensuring that individuals are aware of the restrictions and the reasoning behind them, ultimately contributing to the overall safety and efficiency of airfield operations.