Define the term "agent of opportunity" in the context of CBRN threats.

The term "agent of opportunity" in the context of CBRN (Chemical, Biological, Radiological, and Nuclear) threats refers to a substance that is readily available and can be easily weaponized to cause harm. This implies that it is not a specialized or rare material, but rather one that individuals or groups might readily acquire or have access to, which increases the risk of it being used for malicious purposes.

Materials considered agents of opportunity are typically found in everyday contexts, such as industrial settings, laboratories, or even households, which makes them particularly concerning for first responders and medical personnel. Understanding this concept is crucial for preparedness and response strategies because it highlights the importance of monitoring and controlling substances that may not initially seem dangerous but have the potential for misuse in a CBRN context.

In contrast, other options describe various categories of substances, but they do not align with the concept of an "agent of opportunity." For example, a rare substance that cannot be weaponized would unlikely be a concern in the context of opportunistic threats, as its rarity and non-weaponization eliminate the potential for misuse. Similarly, highly regulated chemicals that are not used in warfare wouldn’t qualify as "agents of opportunity," since their regulation often limits access.