Alan and Sara Winthrop are a married couple who file a joint income tax return. They have two children, so they claim a total of 4 exemptions. In addition, they have legitimate itemized deductions totaling $25,750. Their total income from wages is $216,500. Assume the following tax table is applicable: Married Couples Filing Joint Returns You Pay This Amount on the Base of the Bracket If Your Taxable Income Is Plus This Percentage on the Excess over the Base 10.0% 15.0 25.0 28.0 Average Tax Rate at Top of Bracket 10.0% 13.8 19.4 22.4 Up to $18,450$ $18,450-$74,900 $74,900-$151,200 $151,200- $230,450 $230,450- $411,500 $411,500- $464,850 Over $464,850 1,845.00 10,312.50 29,387.50 33.0 27.1 51,577.50 111,324.00 129,996.50 35.0 28.0 39.6 39.6 What is their average tax rate? a. 18.94% b. 16.68% C. 17.71% d. 19.15% e. 20.59%