Not Only Do Members of the Same Family Share Similar

Multiple Choice

Not only do members of the same family share similar patterns of body growth and development,but members of the same ethnic groups also show similar rates of growth and final body proportions.This suggests that

A) it is difficult to determine norms of physical growth.
B) there is great individual variation in physical growth.
C) cultural factors alone are responsible for physical development.
D) genetic factors play an important role in physical development.