Who decides what must be counted during munitions account inventories?

The decision on what must be counted during munitions account inventories rests with the Munitions Accountable Systems Officer (MASO). The MASO is responsible for the accurate tracking and management of munitions and ensures that all items in the inventory comply with regulatory guidelines. This role is crucial for maintaining accountability and accuracy in munitions management, as the MASO oversees the munitions accountability system, ensuring that all items are properly accounted for and that discrepancies are resolved.

The other roles, such as the inventory team leader, logistics officer, and base supply officer, may contribute to the logistics and organizational aspects of inventory management, but they do not hold the primary responsibility for deciding what must be counted. The MASO's authority in this area is pivotal for the integrity of the munitions inventory process, making this the correct answer.