Janet thinks that she may have made an error on a Federal income tax (FIT) return that she filed in a prior year, whereby she overpaid her FIT. If true, she would be entitled to a FIT refund if she files a timely amended FIT return claiming the refund. As she is not familiar with the FIT law, she contacts you because she would like to read the actual law in this area that specifies the time by which she must file the amended return for it to be timely. Based on a keyword search in Checkpoint, identify what IRC section and subsection provides guidance on the time requirement by which a taxpayer may claim a refund of an overpayment of FIT attributable to a previously filed FIT return. Your response should appear as follows: ______(_____)