For the following independent cases, determine whether economic income is present and, if so, whether it must be included in gross income (that is, is it realized and recognized for tax purposes?).
a. Asia owns stock that is listed on the New York Exchange, and this year the stock increased in value by $20,000.
b. Ben sold stock for $10,000 and paid sales commission of $250. Ben purchased the stock several years ago for $4,000.
c. Bessie is a partner in SULU Enterprises LLC. This year SULU reported that Bessie's share of rental income was $2,700 and her share of municipal interest was $750.