Which Best Exemplifies the Process of Cultural Evolution

Which best exemplifies the process of cultural evolution?

A) The fact that different eye shapes are found within individuals in the same ethnic group
B) Inheriting a stronger left arm than a right arm because in the past,this allowed for the faster cutting of grains and more food for families
C) The dramatic shift from Communism to Democracy seen in the Soviet Union in the 1980s
D) Greater height in current generations than in past generations because in past generations,food that needed to be gathered was closer to the ground