登录之后可查看解析

B is corrent. Although gains and losses incurred in sales transactions between a partnership and its partners are generally recognized, a loss is disallowed if incurred in a transaction between a partnership and a partner owning (directly or constructively) more than a 50% capital or profits interest. Since Lydia’s partnership interest does not exceed 50%, she realizes and recognizes a long-term capital loss of $9,000 - $4,000 = $5,000 from the sale of stock.
A is incorrect. All $5,000 of the loss can be recognized. 
C is incorrect. All $5,000 of the loss can be recognized.  
D is incorrect. All $5,000 of the loss can be recognized.