the following information is available for Bob and Brenda Horton, a married couple filling a joint return for 2020. Both Bob and Brenda are age 32 and have no dependents. salaries. $200000 Interest income. $12000 Deductible IRA contributions. $11000 Itemized deductions. $25600 Withholding. $31000 a) what is the amount of their gross income? b) what is the amount of their AGI ? c) what is the amount of their taxable income? d) what is the amount of their tax liability (gross tax,) rounded to the nearest dollar? e) what is the amount of their tax due or (refund due)?