Which of these is a form of early black music used by vocalists when they improvise?
O A. work songs
O B. hard bop
O C. New Orleans jazz
O D. swing

The answer is A

explaination:

whenever slaves would be sent to work on a plantation they would sing work songs to help let time pass

photography had emerged as an elite art pursued by a few creative individuals for a few wealthy patrons. but now, said bauldelaire, it was succumbing to "the great industrial madness of our times." it was becoming a mass production industry that catered to middle-class tastes, including a taste for gadgetry. the stereoscope, the first 3d imaging system, had turned looking at photographs into parlor entertainment. a "thousand hungry eyes were bending over the peepholes of the stereoscope as though they were the attic-windows of the infinite.