Which Behavior Genetics Research Result Provides the BEST Evidence of the Importance

Multiple Choice

Which behavior genetics research result provides the BEST evidence of the importance of environmental factors in the development of a particular trait?

A) An adoption study shows that the correlation between adoptive children and their adoptive parents is higher than is the correlation between the children and their biological parents.
B) An adoptive twin study shows that the correlation between identical twins who grew up together is higher than is the correlation between identical twins who grew up apart.
C) A twin study shows that the correlation between identical twins is higher than is the correlation between same-sex fraternal twins.
D) A family study shows that the correlation between siblings reared together is higher than is the correlation between siblings reared apart.