The portfolio manager defines the portfolio based on a listing of already existing work in the organization and selects the right components in order to be able to prioritize them. What do you use for

Prioritization is a technique applied after components have already been identified and inventoried; it is not the tool used to initially list existing organizational work for portfolio definition.

Inventory of Work is a general informal concept, not the specific PMI-defined artifact used in the portfolio definition process to formally catalog existing organizational work.

The Portfolio Component Inventory is the PMI-defined artifact used to document and list all existing work in the organization - including projects, programs, and operational work - that serves as the structured basis for defining what belongs in the portfolio. It provides the comprehensive, organized listing needed before components can be evaluated, selected, and prioritized.

Elicitation techniques are used to gather information and requirements from stakeholders but are not the specific artifact used to list and define existing work as the foundation for portfolio definition.