How did you find the answer to this question (b)??

How did you find the answer to this question (b)??Mountaineer, Inc. has the following results: Regular corporate tax liability Taxable income Preferences Adjustments $400,000 2,000,000 500,000 (200,000) What is the amount of the alternative minimum tax? a. $0 b. $60,000 c. $100,000 d. None of the above.