Which of the following statements is most correct?
a. Tax preference items for the alternative minimum tax are always added back to regular taxable income.
b. Itemized deductions that are added back to regular taxable income for the alternative minimum tax are preference items.
c. Tax preference items for the alternative minimum tax can be an increase or decrease to regular taxable income.
d. All taxpayers are able to deduct the full exemption in the calculation of the alternative minimum tax.