Which skill must a performer, composer, and listener all possess? A. improvisiation
B. active listening
C. vocal skills
D. sightreading skills

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