Phil files Form 1040 showing a total tax due of $4,000. The IRS audits his return and determines he should have paid $10,000. The understatement of $6,000 is 60% of the amount he should have paid and is more than $5,000. Therefore, Phil is assessed a penalty for which amount on his $6,000 underpayment? a. $1,200 b. $1,500 c. $2,000 d. $3,000 Please explain and show the work. Thank you