The consistency check in SAP IBP ensures the planning area’s configuration (e.g., time profile, key figures) is valid. Changes to the time profile must maintain structural integrity, as per SAP IBP’sconfiguration rules.

Option A: Add a new time profile level to the time profileThis is incorrect. Adding a new level (e.g., quarter) requires updating key figure planning levels and data, potentially breaking consistency until fully aligned.

Option B: Change the numbering hierarchy of the period IDs in the time profileThis is incorrect. Altering period ID numbering (e.g., PERIODID0 to PERIODID1) disrupts existing data mappings, causing consistency check failures.

Option C: Change the past and future horizon of the level in the time profileThis is correct. Adjusting the horizon (e.g., extending from 12 to 24 months) affects data visibility but not structural consistency, allowing a successful check, per SAP IBP’s time profile documentation.

Option D: Change the description of an attribute in the time profileThis is correct. The description (e.g., "Week" to "Weekly") is metadata and doesn’t impact data integrity, ensuring a successful consistency check, per SAP IBP’s configuration flexibility.

Thus, C and D are safe changes, per SAP IBP’s official consistency check behavior.