Choice "D" is correct. With respect to a timely filed return, the general rule is that the IRS can assess additional tax within three years from the later of the return's due date (plus extensions, if any) or the date the return was filed. A taxpayer's inadvertently overstating deductions in an amount equal to 15% of gross income will not trigger any of the exceptions to the general rule.Choice "b" is incorrect. There is no statute of limitations when a taxpayer willfully attempts to evade tax in filing income tax returns.Choice "c" is incorrect. A six year statute of limitations applies when a taxpayer omits from gross income an amount in excess of 25% of the gross income stated on the income tax return. For purposes of the "six year" statute, gross income is not reduced by cost of goods sold.Choice "a" is incorrect. There is no statute of limitations when the IRS files (actually, "executes") a substitute income tax return when the IRS learns that a taxpayer failed to file a return.