Where can specific guidance on conducting courts and boards of inquiry be found?

The correct choice provides the specific guidance required for conducting courts and boards of inquiry as outlined in JAGINST 5830.1A. This instruction is tailored to address the procedures and standards necessary for the establishment and operation of courts and boards within the jurisdiction of the Judge Advocate General. It covers key aspects such as the composition, authority, conduct, and reporting requirements, ensuring that the process is aligned with legal standards and practices.

The other options, while related to aspects of military law and legal procedures, focus on different subjects. For instance, JAGINST 5800.1A relates to legal assistance and the provision of legal services, while JAGINST 5805.1A deals with administrative actions concerning legal personnel. Similarly, JAGINST 5810.1A pertains to manual procedures and operations related to legal documents and services. Each of these instructions serves a distinct purpose and is not the designated guide for courts and boards of inquiry.