问题如下：
Firms that claim to comply with the GIPS standards must disclose the use of a sub-advisor and the:
选项：
A.identity of the sub-advisors.
B.period the sub-advisors were used.
C.investment strategies employed by the sub-advisors.
解释：
B is correct.
Provision I.4.A.25 states, "For periods beginning on or after 1 January 2006, firms must disclose the use of a sub-advisor and the periods a sub-advisor was used." (See Section 3.11 of the reading.)
为什么c不对
