Research Involving Family and Adoption Studies Have Demonstrated That

Research involving family and adoption studies have demonstrated that

A) siblings reared together and cousins reared together have similar IQ correlations.
B) the higher the percentage of shared genes between people, the less similar their IQ correlations will be due to environment.
C) the correlations between the IQ scores of cousins reared together are negative.
D) the higher the percentage of shared genes between people, the higher their IQ correlations will be.