Researchers Wells,Graham,and West Have Conducted a Number of Studies on Male

Researchers Wells,Graham,and West have conducted a number of studies on male behaviour in bars,observing both bouncers and patrons.What conclusions have they reached?

A) Bouncers used excessive aggression against bar patrons when the bouncers were intimidated and needed to defend themselves.
B) No conclusions can be drawn as it was just observational research.
C) If threats or fights occur it is usually in response to direct provocation.
D) They documented the existence of a macho subculture among male bar patrons.
E) Patrons in bars often provoke the bouncers to become aggressive.