How did the Royal Marines demonstrate their capability during the Selbourne scheme?

The Royal Marines demonstrated their capability during the Selbourne scheme primarily through the integration and reduction of professional differences between Royal Navy (RN) and Royal Marines (RM) officers. This initiative was critical in fostering a more cohesive command structure and understanding between the two branches, enhancing operational effectiveness in joint missions. By aligning the two forces more closely, the Royal Marines were able to leverage the strengths of both entities to execute combined operations more efficiently.

This integration was not merely about administrative changes; it involved practical training scenarios and a shift in culture that encouraged collaboration and mutual respect. As a result, this approach positioned the Royal Marines to operate seamlessly alongside their RN counterparts, demonstrating their operational readiness and evolving capabilities within a modern military context.

The other options, while relevant to different aspects of military operations and personnel management, do not highlight the specific achievements within the framework of the Selbourne scheme as effectively as the integration of professional roles did. This focus on eliminating professional divides was fundamental in enhancing the operational capacity and readiness of the Royal Marines during that period.