Which operating condition requires a 20-minute time warning for door bundle prep?

The correct option refers to nighttime operations, which necessitate a 20-minute time warning for door bundle preparation. This is primarily due to the increased complexities and challenges associated with conducting parachute operations during low visibility conditions inherent to nighttime. Proper preparation is crucial to ensure that jumpmaster and crew members can safely manage the increased risks involved in nighttime jumps.

In nighttime settings, there is a greater need for coordination and communication, as visual cues are limited and the likelihood of errors can increase. The 20-minute warning allows adequate time for all necessary checks, equipment readiness, and ensures that jumpers are fully prepared for the operation.

While combat operations, daytime operations, and training missions have their own protocols, the specific requirement for a time warning is particularly critical in the context of nighttime operations where visibility and situational awareness are significantly reduced.