What defines a 'booby trap'?

A booby trap is specifically defined as an explosive device that is designed to be activated by the unintended actions of a victim, effectively turning the victim's innocuous movements or behaviors into triggers for the device. This distinguishes booby traps from other types of explosive devices that may be activated by more predictable or intentional methods. The key characteristic is the element of surprise and the reliance on the victim's action, making it a deceptive and insidious form of explosive hazard.

The other options do not accurately capture this critical aspect of a booby trap. For example, while devices that deter enemy movement could be considered traps, they typically do not rely on unsuspecting or unintended actions of individuals to activate them. Safety mechanisms are intended to prevent detonation, rather than exploit the victim's actions. Finally, warning systems are meant to alert individuals about potential hazards instead of being a hidden danger that triggers an explosion. Thus, the distinct nature of a booby trap as an ambush-style explosive device is what makes this definition the most accurate.