Final answer:
Benny Carter was known for advocating for civil rights, participating in interracial collaborations, and breaking racial barriers in the entertainment industry. He did not serve as a spokesperson for a segregationist organization.
Step-by-step explanation:
Benny Carter achieved all of the following in his fight against racism EXCEPT: c) Serving as a spokesperson for a segregationist organization. In his career, Carter was known for advocating for civil rights through his music, participating in interracial collaborations, and breaking racial barriers in the entertainment industry. These actions align with the spirit of the Civil Rights Movement, which was characterized by various forms of activism, including legal challenges, grassroots mobilization, and the use of music and the arts to promote social change. As an artist, Carter contributed to these efforts by using his platform and talents to challenge racism and promote equality. There is no evidence to suggest that he ever served as a spokesperson for a segregationist organization, which would have been contrary to the ethos of the civil rights cause he supported.