Final answer:
A 21 gun salute is rendered for the President of the United States, a foreign head of state, and a deceased military officer.
Step-by-step explanation:
A 21 gun salute is rendered for all of the options mentioned in the question: a) For the President of the United States, b) For a foreign head of state, and c) For a deceased military officer.
A 21 gun salute is a traditional military honor that involves firing cannons or other firearms in a specific sequence. It is usually performed during official ceremonies, such as when a high-ranking dignitary visits or during military funerals. The number 21 is significant because it is symbolic of the highest honor, as it represents the highest military salute.
For example, when the President of the United States travels to other countries, a 21 gun salute is often given as a sign of respect and hospitality. Similarly, when a foreign head of state visits the United States, they may be honored with a 21 gun salute. Additionally, when a military officer passes away, they may receive a 21 gun salute as a final tribute.