单选题 Which of the following is NOT a key characteristic of the Global Investment Performance Standards (GIPS) ? GIPS : A. represent the highest performance measurement and presentation practice worldwide. B. are ethical standards for investment performance presentation to ensure fair representation and full disclosure of an investment firm's performance history. C. require managers to include all actual fee - paying and non - fee - paying discretionary portfolios in composites defined according to similar strategy and/or investment objective.