When must a military salute be given?

The correct context for when a military salute must be given is when both the service member and the superior officer are in uniform. This practice reflects the military's traditions and protocols regarding respect and discipline. Saluting serves as a formal gesture of acknowledgment and respect between ranks, highlighting the hierarchical structure that exists within military organizations. When both individuals are in uniform, it emphasizes their roles and the significance of the salute, reinforcing camaraderie and respect for rank.

The other choices either misinterpret the instances when a salute should be given or suggest practices that do not align with military customs. For example, saluting in civilian clothing does not adhere to the proper military protocol that necessitates both parties to be in uniform. Similarly, the idea that a salute should occur at least once a day to any officer does not align with the specific occasions that call for a salute. Lastly, saluting whenever entering a building is also incorrect, as saluting protocols are based on status and uniformity, not simply on entering a space.