问题如下：
Which of the following is not appropriate in the performance presentation to a firm that claims to comply with the GIPS standards?
选项：
A.The firm must present the cumulative composite return and benchmark returns at the end of each annual period.
B.The firm must present either the percentage of the total firm assets represented by the composite or the amount of total firm assets at the end of each annual period.
C.If a composite includes non-fee-paying portfolios, the firm must present the percentage of composite assets represented by non-fee-paying portfolios as of each annual period end.
解释：
A is correct.
考点：Presentation and reporting
解析：A选项是GIPS推荐披露的，而非必须披露的。B选项，每一年度结束时，公司需要报告披露公司总的资产数目或者报告披露composite资产对于公司总资产的所占百分比，正确。C选项，如果composite中包含了不付费的基金组合，那么公司就必须于每一年度末报告不付费资产组合占composite的百分比情况，正确。
请问为何A不正确？return不是必须披露的吗？
