Which of the following is NOT a requirement for a patent?

The requirement that is not necessary for obtaining a patent is confirmation of market demand. In the context of patent law, the criteria that must be met for an invention to be patentable include utility, novelty, and non-obviousness.

Utility means that the invention must have some useful purpose; it has to provide some genuine benefit to society. Novelty requires that the invention is new, meaning it has not been previously disclosed to the public. Non-obviousness indicates that the invention must not be an obvious development to someone skilled in the relevant field at the time of the patent application.

Market demand, however, does not factor into the patentability of an invention. An inventor can obtain a patent even for an invention that no one may want to buy or use, as long as they fulfill the legal criteria of utility, novelty, and non-obviousness. Therefore, market demand is irrelevant in the determination of whether a patent should be granted.