Which of the following best describes the main purpose of the passage

A． To contrast the condition of African-American cinema with that of mainstream cinema
B． To provide an economic explanation for the unpopularity of African-American cinema
C． To criticize the assumptions mainstream audiences allegedly make toward African-American cinema
D． To catalog the attitudes and practices responsible for the unpopularity of African-American cinema
E． To outline the fundamental problem in African-American cinema and its most likely solution