You are a supplier contract specialist.

Supplier contracts in Workday are formal, approved agreements that govern terms such as pricing, dates, and total contract amount with a supplier. Once a contract reaches Approved status, its terms are locked and cannot simply be overwritten through direct editing. Per the Official Workday Pro Procure-to-Pay Guide, the correct mechanism for changing approved contract data, such as the contract amount, is to initiate a Create Contract Amendment business process. The amendment creates a new version of the contract with the corrected amount while preserving the original document and a full audit trail of the change, including any required re-approval. Option A is incorrect because catalogs hold pricing for items, not the overall contract amount, and changing a catalog does not alter the contract record itself. Option B is incorrect because an attachment is purely supplementary documentation; it does not update the actual data field driving contract value or downstream processing. Option C is incorrect because invoices are transactional documents created against POs or contracts during the procure-to-pay cycle and cannot be used to replace or modify a contract record.