Final answer:
Comprehensive income includes unrealized gains and losses on available-for-sale securities, but not gross margin, operating income, or interest expense according to the FASB's framework.
Step-by-step explanation:
According to the FASB's conceptual framework, comprehensive income includes all changes in equity during a period, except those resulting from investments by owners and distributions to owners. Among the options provided, unrealized gains and losses on available-for-sale securities are included in comprehensive income. These reflect changes in the fair value of securities that have not yet been realized through a sale. Gross margin, operating income, and interest expense are components of net income rather than comprehensive income.