Which of these is not correct; about a patent
A patent is a set of exclusive rights granted by a state (national government) to an inventor or their assignee for a limited period of time in exchange for a public disclosure of an invention.
—>> The grant of patent effectively gives the inventor or more commonly his employers, a monopoly to work the invention to the exclusion of others for a period of time, exceeding 20years.
patent usually refers to a right granted to anyone who invents or discovers any new and useful process, machine, article of manufacture, or composition of matter, or any new and useful improvement thereof
that patent law uses property rights to stimulate private investment in new and useful and non obvious technologies.