During the examination process, what can the PTO argue against patentability?

The ability of the PTO (Patent and Trademark Office) to argue against the patentability of an invention primarily relies on the evaluation of prior art. Conflicting prior art references indicate that similar or identical inventions exist, which may establish that the invention in question does not meet the criterion of novelty or non-obviousness as required under patent law.

Prior art can encompass previously issued patents, published patent applications, and other public disclosures that anticipate or render obvious the claimed invention. If the PTO can find prior art that conflicts with the applicant's claims, it can effectively argue that the invention is not new, thereby challenging its patentability.

In contrast, market viability and absence of similar inventions do not directly pertain to patentability requirements under U.S. patent law. The optionality of an invention's benefits might also be considered as a factor in evaluating usefulness but is not a ground for rejecting patent claims based on statutory criteria. The focus is on the existence of conflicting prior art, making this the correct basis for the PTO's argument against patentability.