Identical Twins Reared Together and Apart Tend to Score Similarly

Multiple Choice

Identical twins reared together and apart tend to score similarly on standardized measures of intelligence. Which of the following statements does this finding support?

A) Intelligence levels are based on environmental factors for both twins reared together and twins reared apart.
B) Environmental factors are stronger influences on twins raised together compared to twins reared apart.
C) The "intelligence gene" is identical in both twins reared together and reared apart.
D) Genes are an important source of individual variations in intelligence scores.