A Recent Study by Sociologists Ruben May and Pat Goldsmith

A recent study by sociologists Ruben May and Pat Goldsmith found that:

A) bouncers at nightclubs' doors periodically use differences in clothing styles to exclude black men.
B) bouncers at nightclubs' doors are more reluctant to allow groups of black men entry than groups of white men.
C) bouncers at nightclubs' doors are more likely to refuse entry if a black man is drunk and disorderly than if a white man is drunk and disorderly.
D) All the above