In 1975, Riveria Company had acquired copyrights for $750,000 on several literary works from some obscure 18th century authors. These copyrights were fully amortized by 2015. In early 2015, a new anthropological discovery made these copyrights worth $2,500,000. As a result, Riveria should report which of the following in its financial statements for 2015?

$2,500,000 as an extraordinary item

Cannot be recognized under U.S. GAAP in the financial statements

$2,500,000 as a holding gain

$750,000 as copyrights-based recovery of value limited to historical cost