Which alert is appropriate for individuals with a history of drug abuse?

The appropriate choice in this context is a Caution Indicator. This alert is specifically designed to provide critical information about individuals who may present certain risks, such as those with a history of drug abuse. A Caution Indicator is used to inform personnel that additional care or consideration may be needed when handling situations involving these individuals. This ensures that responders are aware of any potential dangers or complications that may arise during an encounter, leading to more informed decision-making and enhanced safety.

In contrast, the other types of alerts do not carry the same level of specificity concerning an individual's behavior or risks associated with drug abuse. A Notification typically serves a more general purpose, while an Advisory Signal may not focus on personal history that directly affects safety. A Warning Notice, while focused on potential threats, does not specifically address the nuances of an individual's background in the context of drug-related issues. The Caution Indicator thus stands out as the most appropriate tool for alerting responders to specific risks associated with individuals who have a history of drug abuse.