Which document is part of the directive series regarding correspondence preparation standards?

The correct choice is tied to the specific role that OPNAVINST 5215.17 plays in the context of correspondence preparation standards. This document falls under the Navy's series of directives, which are known for establishing consistent protocols for official communication and documentation within the Navy. OPNAVINST 5215.17 specifically outlines the standards and procedures for the preparation of correspondence, ensuring clarity, professionalism, and uniformity in official documents.

This directive is essential for personnel responsible for writing, reviewing, and processing correspondence, as it provides the foundational guidelines that must be followed. By adhering to these standards, Marine Corps personnel can ensure that their communications are effective and meet the expectations set by the Navy’s operational framework.

In contrast, the other documents listed, while they also pertain to correspondence or documentation, do not specifically provide the same comprehensive standards for correspondence preparation as OPNAVINST 5215.17. SECNAV M-5210.2 primarily focuses on the management of records, MCO 5216.5 deals with correspondences within the Marine Corps context but doesn't have the same scope as OPNAVINST 5215.17, and NAVPERS 15000 addresses personnel administration rather than correspondence standards.