Requisition sourcing is the process by which buyers review approved requisition lines and determine how they will be fulfilled, including assigning suppliers and pricing, and Workday provides tools to help buyers manage this workload efficiently across many requisitions and lines. The Official Workday Pro Procure-to-Pay Guide confirms that the requisition sourcing console can be used to manage requisitions, giving buyers a centralized view to filter, review, and act on requisition lines awaiting sourcing. Option A is incorrect because there is no requirement that all lines of a requisition be sourced from the same supplier; different lines can be sourced to different suppliers based on what each line requires. Option C is incorrect because items on a requisition do not have to be sourced all at the same time; sourcing can occur at different times for different lines. Option D is incorrect because, during manual sourcing, the buyer can in fact change or assign the supplier for a requisition line, which is a core part of the sourcing action rather than a restriction.