Final answer:
In outsourcing product development, the acquirer needs to send a Request for Proposal (RFP) and Requirements Specification document to the supplier early on.
Step-by-step explanation:
In outsourcing product development, the acquirer needs to send a Request for Proposal (RFP) document to the supplier early on. The RFP outlines the requirements and expectations for the project. Additionally, the acquirer should send the Requirements Specification document to clearly define the functional and non-functional requirements of the product.