USMC Embarkation Practice Test - Comprehensive Practice Exam & Study Guide

The correct response is that a Letter of Instruction (LOI) includes guidance for military operations. An LOI serves as an important tool for communicating essential operational details, objectives, and directives to ensure cohesion and understanding among units involved in a mission. This guidance can cover a range of topics including mission parameters, timelines, force requirements, and coordination among various units, all aimed at achieving the mission's success.

While the other options might be relevant in specific military contexts, they do not represent the primary purpose of an LOI. Financial details for cargo, reports on aircraft performance, and lists of passengers could be communicated in other documents or formats, but they are not typically the central focus of an LOI. Instead, the LOI is distinctly focused on operational instructions, making it crucial for effective mission planning and execution.