The answer is B, it is the first time black and white actors appeared on stage together on Broadway
Explanation:
As at that time, Show Boat was able to address the social menace of its time which was social evolution and black racism. With the idea of a cast that incorporated both the blacks and the white, it was the first musical on Broadway to feature both white and black performers.
I think it would be Candidate H. They have worked at a company that was accused of labor violations. They would know first hand what that was like & most likely be willing to protect workers & minority rights.