In 2018, Susan (44 years old) is a highly successful architect and is covered by an employee-sponsored plan. Her husband, Dan (47 years old), however, is a Ph. D. student and unemployed. Compute the maximum deductible IRA contribution for each spouse in the following alternative situations. a. Susan’s salary and the couple’s AGI before any IRA contribution deductions is $193,000. The couple files a joint tax return. b. Susan’s salary and the couple’s AGI before any IRA contribution deductions is $123,000. The couple files a joint tax return. c. Susan’s salary and the couple’s AGI before any IRA contribution deductions is $83,000. The couple files a joint tax return. d Susan’s salary and her AGI before the IRA contribution deduction is $83,000. Dan reports $5,000 of AGI before the IRA contribution deduction (earned income). The couple files separate tax returns.