Regarding Diversity Issues, Systems Theorists

Regarding diversity issues, systems theorists

A) have not adequately addressed issues of culture and ethnicity.
B) have focused therapeutically not on sexual orientation itself but on the degree to which the system accepts the sexual orientations of its members.
C) have focused on how gender bias damages the disempowered members of a system which, in U.S. culture, are females.
D) all of the above
E) none of the above