B is correct. Selecting a top-performing portfolio to represent a firm’s overall investment results for a specific mandate, also known as using representative accounts, is a misleading practice that is not allowed under the GIPS standards.

A is incorrect because including terminated portfolios is consistent with the GIPS standards. If the firm instead presented a performance history that excludes terminated portfolios, however, such a practice would be misleading and not allowed under the GIPS standards.

C is incorrect because presenting performance for its mandate covering all periods since the firm’s inception is consistent with the GIPS standards. If the firm instead presented performance for a selected period during which it produced excellent returns or outperformed its benchmark, however, such a practice would be misleading and not allowed under the GIPS standards.

B是正确的。选择一个表现最好的投资组合来代表一个公司的整体投资结果，也被称为使用代表性帐户，是一种误导性的做法，根据GIPS标准是不允许的。

A是不正确的，因为GIPS的标准要求包括终止的投资组合.反而不包含到期投资组合，才违反GIPS。

C是不正确的，因为自公司成立以来，其授权的所有期间的表现都与GIPS标准一致,没有违反GIPS。