Which groups engage in illegal activities that threaten security?

The correct choice highlights that criminal elements are individuals or organizations that engage in illegal activities, which can encompass a wide range of actions from organized crime to cybercrime. These activities pose significant threats to national and personal security, as they often involve illicit intentions such as theft, trafficking, and espionage.

Criminal elements operate outside the law and frequently exploit vulnerabilities in systems or individuals for illicit gain, making them a core focus in counterintelligence efforts. Understanding the nature of criminal activities and the groups that partake in them is crucial for enhancing security measures and effectively reporting such threats.

In contrast, other groups like technical experts, government officials, and volunteers typically operate within legal and ethical frameworks, contributing positively to security and stability rather than undermining it. Therefore, criminal elements are uniquely positioned as a primary concern when addressing threats to security.