Answer:
d. a prior period adjustment.
Step-by-step explanation:
Correction of the error when discovered in the next year should be treated as a prior period adjustment. This is basically because the error was already recorded in the past financial report. Since these reports are final and cannot be changed, then the correction to this error needs to be implemented in the next year's financial report and would reflect on that year's income taxes. The process of doing this is known in accounting as a prior period adjustment