In Terms of Intellectual Development, One Important Conclusion from Adoption

In terms of intellectual development, one important conclusion from adoption and twin studies is that the more two people in a family are alike genetically, __________.

A) the higher the correlation in their IQ scores
B) the less correlated their IQ scores are
C) the greater the diversity in subskills on an intelligence test
D) the greater the likelihood that there will be children with very low IQ scores in the family