In keeping with a modernization of corporate statutes in its home state, UMC Corporation decided in 2021 to discontinue accountin for reacquired shares as treasury stock. Instead, shares repurchased will be viewed as having been retired, reassuming the status an unissued shares. As part of the change, treasury shares held were reclassified as retired stock. At December 31, 2020, UMC's balan sheet reported the following shareholders' equity: Common stock, $1 par Paid-in capital-excess of par Retained earnings Treasury stock (6 million shares at cost) Total shareholders' equity (5 in millions) $ 225 900 1,020 (35) $2,110 Required: a. Identify the type of accounting change this decision represents. b. Prepare the journal entry to effect the reclassification of treasury shares as retired shares.