Which of the following can lead to a later buyer obtaining good title to a patent?

The correct response highlights the principle of good faith purchases in patent law. A later buyer who is unaware of a prior sale and who compensates for the patent may obtain good title due to the protections afforded to good faith purchasers. This concept is grounded in the idea that a bona fide purchaser who lacks knowledge of any existing claims or encumbrances can secure rights to the property they acquire, assuming they compensate the seller appropriately.

In the context of patent assignments, if the later buyer has no knowledge of the earlier transaction and acts in good faith—meaning they were diligent in their inquiries and genuinely believed they were acquiring valid rights—they may be protected against challenges to their ownership. This protection often arises from statutory provisions aimed at promoting the stability of titles, encouraging commerce, and preventing the disruption of legitimate patent transfers.

The other options present scenarios that do not support good title acquisition effectively. For example, if the later buyer pays nothing, they are unlikely to be recognized as a legitimate purchaser under patent law principles. Also, a delay in recording an assignment does not affect the validity of the sale; however, if the later buyer was not diligent and fails to research prior transactions, they cannot expect protection. Finally, needing special permission to buy a patent suggests complications that typically