When using the retrospective approach for a change in accounting principle, disclosure rules require that: Multiple Choice prior years' income statements presented for comparative purposes be restated to reflect use of the new principle unless it is impractical to do so. all prior years' income statements be restated to reflect use of the new principle, and include a pro forma net income figure of the previously reported income. no prior years' income statements be restated, but a pro forma net income figure be provided to reflect use of the new principle for each year presented. C ) no prior years' income statements be restated, and no pro forma net income figures be provided