3. The IRS calculates the amount of the Underpayment of Estimated Tax by Individuals Penalty based on the tax shown on a taxpayer's original return or on a more recent return that he or she filed on or before the due date. The tax shown on the return is taxpayer's total tax minus his or her total refundable credits. The penalty based on all of the following except: A. The amount of the underpayment B. Expected adjusted gross income C. The period when the underpayment was due and underpaid D. The interest rate for underpayments that we publish quarterly