The correct answer is B) white racism and capitalism.
What the members of the Black Panther Party believed held back African Americans in the United States was white racism and capitalism.
The Black Panther Party was formed by African American Bobby Seale in 1966, in Oakland, California. One of its major goals at the beginning was to form groups of armed black people that patrolled the streets of Oakland, trying to limit the brutality of the Police against African Americans. This created very tense situations that ended up violently confronting the city Police with the African Americans.