单选题 Joanna, CFA, manages several pension accounts and directs most of her trades through the Torrenia Brokerage House. Joanna does this because she believes she gets expedient and low-cost trade execution, and Torrenia provides her with excellent research reports used in the management of these accounts. ZNS, a small brokerage house, has just approached Joanna and said it will execute her trades at half the cost of Torrenia. However, ZNS does not have a research department. If Joanna declines to switch her business to ZNS, has she violated any CFA Institute Standards?

A、 Yes, because she has not obtained explicit permission from her clients to use ZNS.
B、 Yes, because Standard Ⅲ (A) Loyalty, Prudence and Care states that she must minimize trade expenses.
C、 No, if the higher commissions are commensurate with the value of the research service she receives.

【正确答案】 C

【答案解析】[解析] 本题主要涉及执业操守标准Ⅲ(A)(忠诚，谨慎，关注)的相关规定。
根据执业操守标准Ⅲ(A)的规定，会员在选择经纪业务的代理人(经纪行)时，应当以实现客户利益最大化为基本原则。在本题中，尽管ZNS经纪行可以提供较为低廉的经纪服务，但该经纪行没有研究部门，从而无法提供高质量的研究报告。因此，如果Torrenia经纪行可以提供具有较高价值的研究服务且与其收取的交易费用相匹配，则即使其证券交易成本较高，也应继续选择该行为其提供经纪服务。