Which of the following best describes the controversy associated with the opening of the Broadway musical Showboat?单项选择题

Presented a mixed-race relationship in an unambiguously positive light, and posited the idea that jazz could be a high art music, and should be considered America's classical music.

Idealized African-American laborers, and presented "race-mixture" as a moral problem associated with jazz, as a reason to avoid listening to it.

Placed black and white actors on stage together, addressed themes of racism and the mistreatment of African-Americans in the South, as well as "race-mixture" or miscegenation.

Anticipated the 1918 flu and the likelihood of the Great Depression, presented African-Americans in an unambiguously positive light.