On June 1 of the current year, the Olive Corporation sells machinery for $215,000. The company purchased the machinery several years ago for $180,000. As of the date of sale the total depreciation taken for book purposes = $60,000 and the total depreciation taken for tax purposes = $80,000. The M-1 adjustment created by the sale of machinery is:

a. an increase to book income of $20,000.

b. a decrease to book income of $20,000.

c. an increase to book income of $80,000.

d. a decrease to book income of $80,000

. e. None of the above.