Under Current (2020) US GAAP, when a firm makes a "Voluntary" change in Accounting Methods, the firm is required to . . .

A. Restate all previous periods in the "reporting window" as if the new method had been used previously (you may assume that the information necessary to do this is available)

B. Disclose why the firm believes that the "New" accounting method is preferable to the accounting method that was used previously.

C. Both A and B are required when a firm makes a voluntary change in accounting method.

D. None of the above