In 2016, Juanita is married and files a joint tax return with her husband. What is her tentative minimum tax in each of the following alternative circumstances?

a. Her AMT base is $145,000, all ordinary income.

b. Her AMT base is $497,500, all ordinary income.

c. Her AMT base is $145,000, which includes $16,000 of qualified dividends.

d. Her AMT base is $497,500, which includes $16,000 of qualified dividends.