Determine the retirement savings contributions credit in each of the following independent cases. Use Table 9-2.

\begin{tabular}{|l|l|} \hline & Retirement Savings Contributions Credit \\ \hline a. A married couple filing jointly with modified AGI of $37,500 and an IRA contribution of $1,700. \\ \hline b. A married couple filing jointly with modified AGI of $58,000 and an IRA contribution of $1,700. \\ \hline c. A head of household taxpayer with modified AGI of $33,000 and Roth IRA contribution of $1,890. \\ \hline d. A single taxpayer with modified AGI of $12,000 and an IRA contribution of $2,550. \\ \hline \end{tabular} TABLE 9-2 Rates for Retirement Savings Contributions Credit