Which of the Following Provides the Strongest Evidence of the Role

Which of the following provides the strongest evidence of the role of heredity in determining intelligence?

A) The IQ scores of identical twins raised separately are more similar than those of fraternal twins raised together.
B) The intelligence scores of fraternal twins are more similar than those of ordinary siblings.
C) The intelligence scores of identical twins raised together are more similar than those of identical twins raised apart.
D) The intelligence scores of adopted children show relatively weak correlations with scores of adoptive as well as biological parents.