Which document guarantees to the Owner that the successful Contractor will sign a contract?

The Bid Bond is the correct answer because it serves a specific purpose in the context of the bidding process for construction projects. It is a type of surety bond that is submitted by a contractor alongside their bid to assure the project owner that the contractor, upon being awarded the contract, will enter into a contractual agreement and perform the work as outlined. If the contractor fails to sign the contract or fulfill the requirements after winning the bid, the bid bond protects the owner by providing a monetary compensation, typically up to a certain percentage of the bid amount.

In contrast, a Performance Bond guarantees the completion of the project according to the contract terms but is not tied to the initial bidding process. An Insurance Certificate provides proof of insurance coverage rather than guaranteeing a contract signing. The Contractor Agreement is the actual contract that outlines the terms of the project and is not a guarantee of its signing prior to the awarding of the contract.