In the Context of Genetic Influences on Intelligence, a Classic

In the context of genetic influences on intelligence, a classic study in Louisville, Kentucky, found that:  

A) the intelligence quotient scores of dizygotic twins were more alike than scores for any other pairs. 
B) the correlations in intelligence between dizygotic twins were the same as those between other siblings. 
C) correlations between the intelligence quotient scores of children and their foster parents and between those of cousins were strong. 
D) dizygotic twins were more similar than monozygotic twins in spatial memory, ability to categorize things, and word comprehension.