Why do we need to write music in different key signature?​

In music notation, the key signature tells the reader which notes to play sharp or flat throughout the music. If you are playing a song in a certain key, the same notes will be sharp or flat throughout the entire song. ... That means every F and C you encounter in the music are to be played as Fand C.

Explanation:

i believe the answer is: a.  abstract forms were often used to represent human figures.

representing human figures in abstract forms is often used in the geometric period, not hellenistic  period.   during the hellenistic  period,   aesthetic value derived from creating arts which mimic the actual shape of a certain object or individuals.

hope this ! < 3