Which competency refers to the ability to unify and multiply combat power?

The competency that refers to the ability to unify and multiply combat power is indeed related to the concept of combat power itself. Combat power is a critical military principle that encompasses the various elements and capabilities available to a military organization. It includes the synergy of forces, weaponry, technology, logistics, and personnel—all of which can be optimized to achieve strategic objectives during operations.

By understanding and effectively managing combat power, leaders can ensure that their troops are not only able to work together seamlessly but can also leverage their individual strengths to achieve a greater overall effect on the battlefield. This competency emphasizes the importance of coordination and integration among different units and resources, enabling them to become more effective together than they would be operating independently.

The other options refer to different concepts: the Oath to Constitution pertains to the commitment and ethical foundation of service members, influence deals with the ability to affect others' opinions or actions, and leadership styles focus on the various approaches a leader may take to guide their team. None of these directly address the unification and multiplication of combat power in the same tactical sense that the concept of combat power does.