During 2015, a $50,000 loss on the sale of machinery was incorrectly recorded as a factory equipment repair. The error was not discovered until the books were closed and financial statement were issued for 2016. What adjustment is necessary?

No adjustment is necessary to books or financials.

Record a correction to the books for 2015 and 2016 and recall prior financial statements.

Since only income statement accounts are affected, make no entry to the books but recall the 2015 income statement.

Make no entry, but if $50,000 is a material amount, retrospectively adjust the 2015 comparative income statement.