Military officers swear an oath to serve and defend the ______________.

Military officers take an oath to support and defend the Constitution of the United States. This commitment underscores the foundational principles of the nation, which include the rule of law, democracy, and the rights of individuals. The Constitution serves as the supreme law of the land and outlines the structure of government, the powers of leadership, and the rights of citizens. By pledging loyalty to the Constitution, military officers affirm their dedication to uphold these principles above all else.

The other choices, while important elements of service, do not capture the primary focus of the oath. For instance, while military officers do serve the President and the citizens, their authority and actions are ultimately derived from and bound by the Constitution. Therefore, the oath reflects a commitment to the Constitution itself, ensuring that military actions align with the democratic values it represents.