Which of the Following Observations Provides the Best Evidence That

Which of the following observations provides the best evidence that intelligence test scores are influenced by environment?

A) Identical twins raised apart are less similar in their intelligence scores than identical twins raised together.
B) The intelligence scores of children are positively correlated with those of their parents.
C) Identical twins are more similar in their intelligence scores than are fraternal twins.
D) The intelligence scores of siblings raised together are positively correlated.