When an entity is responsible for paying the alternative minimum tax (AMT) due to adjustments related to the timing of income recognition, such as including the excess of market value over option price upon the exercise of qualified stock options for AMT purposes, but not until the shares are sold for regular tax purposes, how might that excess tax be recovered?

a. File a claim for a refund in the year paid.

b. Carry forward to offset against a future AMT liability only.

c. Carry forward to offset against future AMT or regular tax liabilities.

d. Carry forward to offset against a future regular tax liability only.