CSI’s project delivery and CDT materials distinguish clearly between public and private procurement:

Public work (funded and contracted by government entities) is typically governed by statutes and regulations that require:

Formal advertisement,

Clearly defined bidding procedures,

Sealed bids opened publicly at a specified time and place, and

Award to the lowest responsive and responsible bidder, except where law allows other defined selection methods.

Private work, by contrast, is not generally bound by these public procurement statutes. CSI explains that private owners have significantly more flexibility, including:

Not being required to publicly open bids,

Being able to negotiate with one or more bidders,

Rejecting any or all bids, and

Awarding the contract to any responsive and responsible bidder they choose, based on value, qualifications, schedule, or other criteria—not solely lowest price.

Because of this flexibility, CSI emphasizes that a private owner may select a bidder other than the lowest as long as the bidder is responsive (submits a bid per the requirements) and responsible (qualified, capable, and reliable). This matches Option D exactly.

Why the other options are incorrect or misleading:

A. A private owner may waive any informality in the bidding, except for the performance bond.While private owners often can waive bid informalities, CSI does not state any universal rule that the performance bond is a special exception in private bidding. Performance bonds are typically part of the contract requirements after award, not a fixed “unwaivable informality” in bid receipt; treatment of bonding is governed by the owner’s requirements and any applicable law, not a CSI rule unique to private work.

B. Private bids may be opened in private, but the results must be published in a reasonable time.Publication of bid results is a hallmark of public work (transparency and accountability). CSI does not require private owners to publish bid results; private owners may keep them confidential if they wish, unless other obligations apply (e.g., corporate policies).

C. The laws and regulations for private bidding are the same as for public bidding.CSI specifically distinguishes between public and private owners: public owners are constrained by statutes and regulations, whereas private owners have much more discretion. The laws governing public bidding and private bidding are not the same, and this is a key CDT concept.

Thus, the CSI-consistent distinction is that private owners are free to award the contract to a responsive and responsible bidder who is not the lowest, making Option D the correct choice.

Key CSI-aligned references (no links):

CSI Project Delivery Practice Guide – procurement and bidding chapters comparing public and private practice.

CSI CDT Body of Knowledge – sections on bidding requirements, “responsive and responsible bidder,” and differences between public and private construction procurement.