Final answer:
Preventive security measures against drug activity include implementing community engagement programs, providing more recreational facilities, and improving lighting and visibility, while unrestricted late-hour access would be unhelpful.
Step-by-step explanation:
To prevent drug activity on private property as a property manager, the most effective measures would include implementing community engagement programs, increasing the availability of recreational facilities, and enhancing lighting and visibility in common areas. Allowing unrestricted access to the property during late hours would likely be counterproductive. Community engagement programs promote social cohesion and deter crime by nurturing positive community relationships. An increase in recreational facilities provides lawful and positive activities that can deter the costs of crime by offering alternative leisure opportunities. Moreover, better lighting and visibility are known deterrence approaches as they raise the probability of getting caught and thus the costs of committing a crime.