Which of the following ranks is specifically a part of the Navy hierarchy?

The rank that is specifically part of the Navy hierarchy is Chief Petty Officer. This rank is a key leadership position within the Navy’s enlisted ranks, typically associated with significant responsibilities related to the management and supervision of sailors. Chief Petty Officers serve as vital links between the enlisted personnel and the commissioned officers, acting as mentors and leaders to junior sailors.

In contrast, Sergeant Major and Colonel are ranks that belong to the Army and Marines, while Captain is a rank that exists in multiple branches, including the Navy, but typically represents officer ranks rather than being unique to the Navy's enlisted structure. The Chief Petty Officer plays an essential role in the Navy’s mission, contributing to the overall effectiveness and readiness of the naval force.