The Relative Contributions of Heredity and Environment Are Not Additive

The relative contributions of heredity and environment are not additive.This means:

A) genetic loading cannot account for development alone-an environment is required.
B) some characteristics are solely due to heredity and others to environmental conditions.
C) certain characteristics are more linked to heredity and others to environmental conditions.
D) that the person we become is due to X percent nature and X percent nurture.