Often, Psychologists Are Interested in the Degree to Which Genetic

Often, psychologists are interested in the degree to which genetic and environmental factors play a role in determining intelligence, so they study twins raised in different homes and compare them with twins reared together. A potential problem with the interpretation of such results is that

A) all pairs of children in the same household will not necessarily have equally similar experiences.
B) for the twins reared apart, there is a delay between birth and placement in foster homes which may span a critical learning period.
C) prenatal experiences are more similar for twins than for other children.
D) all of these