Which commander is responsible for selecting and training Marine Corps personnel for nuclear weapons security duties?

The Commandant of the Marine Corps holds the responsibility for selecting and training Marine Corps personnel for nuclear weapons security duties. This role includes ensuring that Marines are adequately prepared and qualified to handle the security of nuclear assets, which is a critical function given the strategic importance of such materials.

This command also integrates the policies, training standards, and operational readiness necessary to maintain high security levels around nuclear weapons. The Commandant oversees the appropriate doctrine and training programs, ensuring they align with national security needs and the Department of Defense directives concerning nuclear weapons.

While other commanders, such as those listed in the options, might have their own specialized roles and functions, they do not have the overarching responsibility for Marine Corps personnel specifically involved in nuclear security. The Commandant's direct oversight and focus on readiness in this area make this choice the most accurate.