Example 2 Diamond Corporation, a calendar year taxpayer, has AMTI (before adjustment for adjusted current earnings) of $6 million for 2017. If the corporation's ACE is $15 million*, its tentative minimum tax for 2017 is: . a. $4.2 million. . b. $3.45 million. . c. $2.55 million. d. $2.02 million. . e. None of the above. * Hint: the "ACE" amount includes AMTI Example 2 Diamond Corporation, a calendar year taxpayer, has AMTI (before adjustment for adjusted current earnings) of $6 million for 2017. If the corporation's ACE is $15 million*, its tentative minimum tax for 2017 is: . a. $4.2 million. . b. $3.45 million. . c. $2.55 million. d. $2.02 million. . e. None of the above. * Hint: the "ACE" amount includes AMTI