Who chairs the Military Intelligence Board?

The Military Intelligence Board is chaired by the National Intelligence Officer (NIO) for military issues. This is because the NIO for military issues plays a crucial role in overseeing intelligence related to military operations and assessments. This position involves coordinating with various military and intelligence entities to ensure a comprehensive and coherent approach to military intelligence, allowing for the effective sharing of critical information that impacts national security and military strategy.

The other options represent significant roles within the intelligence and defense community but do not specifically hold the chairmanship of the Military Intelligence Board. The Deputy Director of National Intelligence focuses on broad oversight of the intelligence community, while the Secretary of Defense is responsible for defense policy and military operations at a higher strategic level. The Director of the Defense Intelligence Agency oversees intelligence activities within the Department of Defense but does not chair the Board. The NIO for military issues is specifically tasked to facilitate discussions and decision-making on military intelligence matters, which is why this choice is the correct one.