One Study Discussed in the Text Demonstrated That Infants with a Particular

One study discussed in the text demonstrated that infants with a particular form of one of the genes influencing production of a neurotransmitter associated with effortful attention had lower effortful attention than other infants only when they also were exposed to poor parenting. This study demonstrates which of the following principles?

A) Genetic influences operate in one's environment.
B) Environmental influences operate in one's genetics.
C) Some genetic influences operate regardless of
environment.
D) Some environmental influences operate regardless of genetics.
E) Current research methods often do not allow researchers to separate the influences of genetics and environment.