In which of the following situations would you not render a salute?

The appropriate choice regarding when to not render a salute is tied closely to military customs and protocols. Guarding prisoners is a situation that requires a focus on security and the responsibility of managing those in custody. In this context, the primary duty of the Marine is to maintain control and ensure the safety of both the prisoners and personnel involved. Rendering a salute in this scenario could divert attention and potentially compromise security.

Saluting is a gesture of respect and recognition typically performed under certain circumstances, such as when meeting superiors or participating in formal events. However, when the situation demands a heightened level of vigilance, as in the case of guarding prisoners, it is neither practical nor appropriate to salute. Other situations, like being indoors or in a vehicle, have specific protocols as well, but they don't inherently carry the same level of responsibility that comes with managing prisoners.