Cindy's current year adjusted gross income (AGI) is $300,000 and her current year total tax liability is $60,000. Her immediate prior year AGI is $200,000 with a total tax liability of $40,000. To avoid an underpayment interest penalty, what is Cindy's minimum required total tax payment amount for the current year? $60,000 $54,000 $44,000 $40,000 $36,000