Which order provides physical fitness requirements for the Marine Corps?

The correct choice is MCO 6100.3, which specifically outlines the physical fitness requirements for the Marine Corps. This order establishes the standards that Marines must meet in order to maintain physical readiness, which is a crucial aspect of their training and operational effectiveness.

MCO 6100.3 includes details on the Physical Fitness Test (PFT) and the Combat Fitness Test (CFT), describing the components, scoring criteria, and any necessary exemptions. It emphasizes the importance of physical conditioning for Marines, supporting both individual performance and collective mission success. This order is fundamental in ensuring that all Marines are assessed regularly on their physical capabilities and are prepared for the rigors of their duties.

The other orders listed, while they each pertain to important aspects of Marine operations and policies, do not specifically focus on the physical fitness requirements set forth for Marines.