To whom must all material proposed for release be submitted before the release date?

The correct answer is the Program Security Officer (PSO) because the PSO plays a critical role in ensuring that sensitive information is handled appropriately in accordance with established security protocols and regulations. Before any material pertaining to a special access program is released, it is necessary for it to be submitted to the PSO for review. This ensures that any potential security risks are identified and mitigated before the information is made available to unauthorized individuals or outside entities.

The PSO is responsible for maintaining the security posture of the program, which includes reviewing training materials, reports, and any other communications that could potentially reveal classified or sensitive information. By requiring the PSO's approval before release, the program effectively safeguards its sensitive material and protects national security interests.

Other options, such as the Department of Defense, Government Program Manager, or Chief Security Officer, while relevant to the broader structure of security and oversight in defense programs, do not specifically handle the direct review and approval process of material release within the context of special access programs. The PSO is specifically tasked with reviewing this material in line with established security practices.