Researchers Who Have Analyzed IQ Scores of Adopted Twins Have

Researchers who have analyzed IQ scores of adopted twins have found that identical twins are more like one another in IQ than fraternal twins are.They also have found that IQs of adopted children are more strongly correlated with the IQs of their biological parents than with the IQs of their adoptive parents.These research results suggest

A) that intelligence has a strong genetic component.
B) that a child's biological heritage predicts her lifetime patterns of achievement and accomplishment.
C) that a child's intellectual capacity is fixed at birth.
D) that environment has no impact upon IQ.