Which of the following is not a type of small unit illumination?

The reasoning behind identifying illumination bombs as not being a type of small unit illumination revolves around the intended application and scale of these devices. Illumination bombs are typically designed for broader operational use, often deployed by aircraft to light up large areas for night operations. They provide a widespread illumination effect that supports strategic operations rather than the localized or tactical illumination typically utilized by small units.

In contrast, trip flares, grenades, and ground pop-ups are all designed for small unit operations. They can be employed to quickly and effectively illuminate a specific area, often used in tactical situations to enhance situational awareness or provide light during engagements. These devices are manageable in size and are intended to be used directly within the immediate vicinity of small units, making them suitable for more close-range applications as opposed to the more extensive reach of illumination bombs.