Well, a spectator sport is a sport that many people find entertaining. So, it basically means, that they have turned the sport into an entertaining sport for people to watch. I apologize if that doesn't make sense or if its wrong.
Coarse means rude or rough.
Thus the word that is best associated with the word coarse is B. Roughness.
Roughness is somehow similar to coarse, it shows cruelty or rudeness in some actions or words. Other term that can be used to describe it is being impolite.
