Final answer:
Before appearing before a SSG Board, a Sergeant (SGT) must complete the Basic Leader Course (BLC), which is part of the Noncommissioned Officer Education System (NCOES).
Step-by-step explanation:
To appear before the Staff Sergeant (SSG) promotion board, a Sergeant (SGT) must have completed the Basic Leader Course (BLC), which is the first level of the Noncommissioned Officer Education System (NCOES). The BLC is a month-long course that provides the basic leadership education necessary for SGTs to lead small groups of soldiers and serve effectively as a noncommissioned officer. The NCOES is crucial for career advancement within the U.S. Army, as it ensures NCOs have the education and training needed to perform their duties effectively.