Many composers in the 20th Century created new and entirely novel approaches to music by: Select one: a. writing works without a tonal center or clear sense of meter b. using the new electronically generated sounds. c. incorporating sounds from the music of non-Western cultures. d. all of the above.

The linear perspective changed the quality of art because it gave art a sense of reality. it gave the illusion that the background and surroundings were actually close and/or far and a sense of depth. linear perspective change the quality of art following its birth the renaissance period as they want the art to be more realistic and they believe one way to achieve it is to use the method of linear perspective. it uses the principle of math to realistically portray space and depth in art. 

Iwant to say it might be a or c my friend

Thom bell , bobby martin , and norman harris .

The answer here would be "work ethic."