I want to know the answer to the following question:
Who administered the longest running MP3 patent in the United States?
All the background I'm provided with is that "If only the known MP3 patents filed by December 1992 are considered, then MP3 decoding has been patent-free in the US since 22 September 2015 when U.S. Patent 5,812,672 expired which had a PCT filing in October 1992.". Is that enough to answer the question?