问题如下：
The GIPS standards do not require firms to value portfolios in accordance with:
选项：
A. the definition of fair value.
B. composite-specific valuation policies.
C. generally accepted principles of financial accounting.
解释：
C is correct.
Provision 1.1.A.2 states that, for periods beginning on or after 1 January 2011, portfolios must be valued in accordance with the definition of fair value, and Provision 1.1.A.3 states in pertinent part that firms must value portfolios in accordance with the composite-specific valuation policy. The GIPS standards do not require firms to adhere to the principles of financial accounting. (See Section 3.2 of the reading.)
B为什么是一种requirement？？
