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