Who is the top-ranking official in the U.S Navy?

The correct answer is based on the position of the Chief of Naval Operations (CNO), who is the highest-ranking officer in the U.S. Navy and a member of the Joint Chiefs of Staff. As of the knowledge cutoff in October 2023, Admiral Daryl Caudle serves as the Commander of the U.S. Fleet Forces Command, which places him in a high-ranking position within the Navy. However, it's important to note that the CNO may change over time and must be verified for the most current information.

The other options provided represent various individuals who hold or have held significant roles in the Navy or government but are not the current top-ranking official. For instance, Admiral James Wells Kilby may have served in notable positions but does not hold the title of CNO, and similarly, Vice Admiral Jeffery Czerewko may also occupy an important role that does not designate him as the top-ranking official. The Honorable Marco Rubio is a political figure and a member of the U.S. Senate, which is unrelated to the hierarchy or command structure of the Navy. Thus, none of the others qualify as the highest ranking official in the context of the U.S. Navy's command structure.