Information pertaining to engineer planning can be found in which reference?

The correct reference for information pertaining to engineer planning is FM 4-4. This Field Manual provides essential guidance on the Army's operational concepts and principles specifically related to engineer operations, including planning considerations, techniques, and procedures that engineers must follow in various operational environments. By consulting FM 4-4, personnel can gain a comprehensive understanding of the tools and methods necessary for effective engineering support in military operations.

Other references listed may also deal with military operations, but they focus on different aspects. For example, one might cover broader tactical operations, while another may address specific training requirements or different branches of military service. FM 4-4 distinctly emphasizes engineer planning, making it the most appropriate choice for this question.