Given a text T, and several options, according to the question posed in the text T to choose the most appropriate option from the options as the answer, please directly output the most appropriate option, do not need to output the explanation.

A key feature of the GIPS standards is that:
Option A:they strive to cover the unique characteristics of each asset class.
Option B:firms must adhere to all requirements of the standards to claim compliance.
Option C:actual, discretionary, fee-paying portfolios may be excluded from a composite under limited conditions.

Answer: B