Federal Income Tax Rules Allow Businesses to Use Different Inventory

Federal income tax rules allow businesses to use different inventory costing methods for tax reporting and financial reporting with one exception.Which of the following situations is not allowed by federal income tax rules?
$\begin{array} { l } \text { Inventory Method } &\text { Inventory Method }\\\text { for Tax Reporting } &\text { for Financial Reporting } \end{array}$

a. $\begin{array}{ll}&&\text { LIFO } & &&&&&\text { LIFO } \\\end{array}$
b. $\begin{array}{ll}&&\text { LIFO } &&&&&& \text { FIFO } \\\end{array}$
c. $\begin{array}{ll}\text { Weighted average } &&& \text { FIFO } \\\end{array}$
d. $\begin{array}{ll}&&\text { FIFO } &&&&&& \text { LIFO }\end{array}$