When is the APB updated and formally briefed?

The correct choice reflects the process outlined for updating and formally briefing the Acquisition Program Baseline (APB). The APB is a critical document in the defense acquisition process that establishes the budget, schedule, and performance parameters for a program. It is primarily updated and formally briefed during Milestone Decision Briefs, which occur at specific points in the program lifecycle, known as milestones.

During these briefings, program managers present updates regarding the program's status against the baseline and highlight any changes that might impact the project. This ensures that all stakeholders are aligned on the current goals and objectives, and allows for informed decision-making to proceed to the next phase of the project. Adhering to this schedule helps maintain oversight and accountability, which are essential in managing complex defense acquisition programs.

While other options suggest different intervals for updates, they do not align with the formally recognized process established for APB modifications tied to milestone reviews.