Could use help with part a and b:)

Callen Incorporated has accumulated minimum tax credits of $1.60 million from tax years prior to 2018 . The following are Callen's regular tax before credits for 2018 through 2021. Required: a. Complete the following table to calculate Callen's allowable minimum tax credit each year under the TCJA rules prior to enactme of the CARES Act. b. Complete the following table to calculate Callen's allowable minimum tax credit each year under the CARES Act rules, assuming Callen does not adopt the quickie 2018 refund option. Complete the following table to calculate Callen's allowable minimum tax credit each year under the TCJA rules prior to enactment of the CARES Act. (Negative amounts should be indicated by a minus sign. Enter your answers in whole dollars not in millions.) Callen Incorporated has accumulated minimum tax credits of $1.60 million from tax years prior to 2018 . The following are Callen's regular tax before credits for 2018 through 2021. Required: a. Complete the following table to calculate Callen's allowable minimum tax credit each year under the TCJA rules prior to enactme of the CARES Act. b. Complete the following table to calculate Callen's allowable minimum tax credit each year under the CARES Act rules, assuming Callen does not adopt the quickie 2018 refund option. Complete the following table to calculate Callen's allowable minimum tax credit each year under the CARES Act rules, assuming Callen does not adopt the quickie 2018 refund option. (Negative amounts should be indicated by a minus sign. Enter your answers in whole dollars not in millions.)