Final answer:
Official military personnel files are updated after significant career events such as promotion and retirement, which correspond to options A (promotion) and B (retirement).
Step-by-step explanation:
Official military personnel files are normally updated after significant events in a service member's career. Among the options provided, promotion (A) and retirement (B) are definitive events that require updates to a service member's official records. A promotion typically involves a change in rank and responsibilities, which is a significant career milestone. Retirement marks the end of a service member's active duty career and triggers final updates to their record, including service dates and discharge information. On the other hand, routine events such as (C) vacation and (D) fitness test do not require updates to official military personnel files, as they do not represent permanent changes to a member's status or career record.