GL flux analysis with narratives and thresholds

You are preparing a monthly GL flux analysis.

Inputs:
- Periods compared: {current_period} vs {prior_period}
- Trial balance (both periods): {trial_balance_data}
- Thresholds: absolute {abs_threshold} and % {pct_threshold}
- Known drivers / events: {known_drivers}
- Chart of accounts mapping to FS lines: {coa_to_fs_mapping}

Produce:
1) Variance table by FS line and by key accounts: Prior, Current, $ Var, % Var, Flag (Y/N).
2) Narrative explanations for each flagged variance (2–4 sentences each), written for management.
3) Follow-up questions for account owners (if needed).
4) Suggested reclasses/cleanups (if patterns indicate miscoding).

Keep narratives factual and audit-ready (no speculation without labeling it).