A well-engineered physical protection system should prioritize protection in depth, minimum consequence of component failure, and balanced protection. Protection in depth ensures multiple layers of defense, minimizing the risk of a single point of failure compromising the entire system. Minimum consequence of component failure ensures that if one component fails, the overall system still functions effectively. Balanced protection ensures that all components and potential vulnerabilities are adequately protected. Therefore, these elements combined make option A the most comprehensive and robust choice for a physical protection system.