Which FM is associated with pathfinder operations?

The correct choice is associated with pathfinder operations because FM 3-21.38 specifically covers the techniques and procedures for air assault operations, including the role of pathfinders in coordinating and managing landing zones, drop zones, and other aspects critical to successful air movements. This field manual provides detailed guidance on the skills required for pathfinders to effectively assist in these operations, emphasizing their key responsibilities in ensuring safe and efficient troop movements from air to ground.

Understanding the role of pathfinders is essential for military operations that involve air assaults, and FM 3-21.38 serves as a foundational resource in training soldiers on these critical tasks. The other field manuals listed do not focus specifically on pathfinder operations and instead cover different areas of military doctrine and procedures.