DoD Directive 6000.12 along with what other series directs the obligated service required for participation in the AFHPSP?

The correct answer refers to OPNAVINST 1520.39, which outlines specific policies and procedures related to the Navy's participation in the Armed Forces Health Professions Scholarship Program (AFHPSP). It is essential as it clarifies the obligations and commitments required from Navy personnel who are beneficiaries of this program, ensuring that all participants understand their service requirements following their training.

This directive works in conjunction with DoD Directive 6000.12 by establishing a framework that addresses both the administrative and operational aspects of obligated service. By clarifying roles and commitments, OPNAVINST 1520.39 plays a critical role in maintaining the integrity of the program and ensuring that participants are adequately prepared for their post-education service obligations.

The other options refer to different administrative instructions and manuals that, while important in their own contexts, do not specifically address the required obligated service for participants in the AFHPSP in combination with DoD Directive 6000.12.