Final answer:
Spies are the special class of persons considered unprivileged belligerents as they do not qualify for combatant status like prisoners of war and civilians which are protected under the Geneva Conventions.
Step-by-step explanation:
Among the listed options, spies are typically considered to be unprivileged belligerents. Unlike prisoners of war and civilians who are protected under the Geneva Conventions, spies do not qualify for combatant status or associated privileges. They are considered unprivileged because they do not adhere to the traditional laws of war, such as wearing a uniform and carrying arms openly. Diplomats, on the other hand, enjoy a different set of protections under international law and are not categorized as belligerents.