Determine the retirement savings contributions credit in each of the following cases. Use Table 9-2. Retirement Savings Contributions Credit a. A married couple filing jointly with modified AGI of $37,500 and an IRA contribution of $1,720. b. A married couple filing jointly with modified AGI of $58,000 and an IRA contribution of $1,740. c. A head of household taxpayer with modified AGI of $33,000 and Roth IRA contribution of $1,910. d. A single taxpayer with modified AGI of $12,000 and an IRA contribution of $2,600