Which of the following documents would a project manager utilize to find a vendor for an undefined project?

A Request for Proposal (RFP) is issued when the buyer knows the problem or goal but has not defined the solution, inviting vendors to describe how they would approach the work and at what cost. This is appropriate for an undefined project because it places the burden of solution design on the vendor. An RFP is more open-ended than an RFQ and more committal than an RFI.

An RFI (Request for Information) is used purely to gather market information before requirements are developed, and does not solicit vendor proposals or binding offers.

An RFQ (Request for Quotation) is used when requirements are fully defined and the buyer only needs competitive pricing, which is the opposite of an undefined project.

A SOW (Statement of Work) is a document the buyer creates to describe work to be performed by a vendor, not a tool used to find or solicit a vendor.