Stock agencies are often concerned about what? a. noise b. exclusivity c. photographer degrees d. all of the above

B because if stock companies are excluded then they may not get as much stock and stock is what they need for their cmpanie to keep going.  

B. Exclusivity

Hope this helped :)

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.