1-41One Limitation on the Findings of Genetic Influences on Alcoholism

1-41.One limitation on the findings of genetic influences on alcoholism is that

A) not enough research has been done using twins.
B) there are so many cultural differences in the use of alcohol that it blurs the genetic differences.
C) there have not been enough studies of the majority of children of alcoholics (those who do not become alcoholics) .
D) there has been too much of a focus on the study of the nonalcoholic children of alcoholics.