What rank is categorized as O-6?

The rank categorized as O-6 is known as Colonel in the Army, Air Force, and Marine Corps, or Captain in the Navy. The correct answer in the context of Navy ranks is Captain. This rank is significant as it typically involves commanding a squadron, ship, or higher organizational units, reflecting considerable experience and leadership responsibilities.

Lieutenant, while an important rank, is lower (O-3). Commander, while also a Navy rank, corresponds to O-5. Admiral is a much higher rank, usually in the O-7 to O-10 range, indicating senior leadership positions. Therefore, the choice of Captain as the rank that corresponds to O-6 highlights an important leadership role within the naval hierarchy.