Abigail files a tax return claiming a refund of $5,000. The refund includes $3,200 in refundable tax credits. The IRS determines that her claim for the refundable tax credits is erroneous and denies the claim, preventing her from receiving the $3,200. The IRS determines that the entire claim is more than Abigail is entitled to receive (excessive) and without a reasonable basis. The IRS can assess an erroneous refund penalty totaling what amount? A. $320 B. $480 C. $640 D. $800