Comprehensive income is an important concept in accounting because it represents

A) all changes in equity
B) changes in equity from nonowner sources
C) changes in liabilities minus assets
D) the impact on equity of all transactions

Comprehensive income includes all changes in equity from nonowner sources, such as unrealized gains and losses on available-for-sale securities, foreign currency translation adjustments, and pension adjustments. It does not include all changes in equity as some changes may be from owner sources. Therefore, the most appropriate answer is B.