Final answer:
Zone 4 should be marked with a sign stating "WARNING DRUG INTERVENTION ZONE" to inform individuals that they are entering an area with active drug monitoring and potential stops for questioning by police.
Step-by-step explanation:
The student's question is referring to a sign requirement for a specific zone, namely Zone 4. Given the context provided, which includes a reference to drug intervention and police surveillance, Zone 4 should be clearly marked, and the lighted sign should state "WARNING DRUG INTERVENTION ZONE". This designation is intended to inform individuals that they are entering an area where law enforcement is actively monitoring for drug-related activities and that they could be subject to stop and questioning.
It's important for safety and legal compliance that such zones are clearly marked to warn the public effectively. The presence of a warning such as this serves both a deterrent to potential illegal activities and a notice for law-abiding individuals regarding the presence of increased police activity.