Choice "B" is correct. Gains or losses that are unusual in nature or occur infrequently but not both, are presented as a component of income from continuing operations.
Choice "d" is incorrect. Under U.S. GAAP, extraordinary items are shown net of tax in a separate section of the income statement after income from continuing operations.
Choice "a" is incorrect. Cumulative effects of changes in accounting principle are now shown net of tax as an adjustment to the opening balance of retained earnings in the retained earnings statement. This treatment is called retrospective application. There really are no longer any cumulative effect types of changes in accounting principle. The cumulative effect is merely how the amount of the change is measured.
Choice "c" is incorrect. This is the definition of an extraordinary item under U.S. GAAP.