Which of the following is true regarding the alternative minimum tax (AMT)?

a.The AMT credits may offset 100% of regular tax liability in 2018 or 2019.

b.The amount of the refundable AMT tax credit is equal to 20% of the excess AMT credit for the tax year, over the amount of credit allowable against regular tax liability.

c.AMT credits are not refundable credits for any tax year beginning after 2017 and before 2022.

d.The individual AMT was repealed along with the corporate AMT.