Final answer:
The Secretary of the Air Force (SAF) is the sole approval authority for Air Force policy directives, responsible for ensuring they align with national defense objectives.
Step-by-step explanation:
The only approval authority/authenticator for Air Force policy directives (AFPD) is the Secretary of the Air Force (SAF).
This means that any new policy or changes to the existing policies within the United States Air Force must be authorized by the SAF, ensuring that all directives comply with national defense goals and strategies. I
n the context provided, this excludes other entities such as Major Command (MAJCOM), Field Operating Agencies (FOA), and Direct Reporting Units (DRU) from this specific authority.