A project manager is creating a project charter for a new internal initiative. The sponsor provides a high-level budget but no details on the benefits. What should the project manager do?

Proceed with the charter using the budget provided; benefits will be defined during planning.

Work with the sponsor and stakeholders to define and document the high-level project benefits and success criteria before finalizing the charter.

Refuse to sign the charter until a full business case is provided.

Use industry standard benefits for similar projects as placeholders.