He is one of the leading composers of electronic and serial music. A. John Cage
B. Karlheinz Stockhausen
C. Edgard Varese
D. Philip Glass

the answer is A

Explanation:

John Milton Cage Jr. was an American composer, music theorist, artist, and philosopher.A pioneer of indeterminacy in music, electroacoustic music, and non-standard use of musical instruments,

answer: the feeling it gives you when you look at it.

explanation:

in every single medium of art, you are supposed to feel something that makes it art. like how a song can make you cry, or how a photograph can make you nostalgic. art is very important for expressing yourself as well, when you are happy, sad, depressed, or angry.

it's d. (also remember it's produced physically,visual effects )