ABC Corporation was originally formed in 2015 as a C corporation. In 2017, it became an S corporation. Which of the following accounts, on Schedule M-2 of its Form 1120-S, does ABC Corporation use to track the undistributed retained earnings that have accrued since it became an S corporation? Accumulated adjustments account. Shareholders' undistributed taxable income previously taxed. Accumulated earnings and profits. Other adjustments account