Read this and answer the question. If the question is unanswerable, say "unanswerable".

Proponents of affirmative action argue that by nature the system is not only race based, but also class and gender based. To eliminate two of its key components would undermine the purpose of the entire system. The African American Policy Forum believes that the class based argument is based on the idea that non-poor minorities do not experience racial and gender based discrimination. The AAPF believes that "Race-conscious affirmative action remains necessary to address race-based obstacles that block the path to success of countless people of color of all classes". The groups goes on to say that affirmative action is responsible for creating the African American middle class, so it does not make sense to say that the system only benefits the middle and upper classes.

Other than being race and gender based, what did believers in affirmative action also feel that the system discriminated against?
class