The correct answers are:
C. Differences in intelligence between identical twins must be due to differences in their environments.
D. If identical twins are separated at birth and raised in different homes, yet still have similar intelligence scores, the similarity in their scores are most likely due to hereditary influences.
Since identical twins have the same genetic material, the only difference between them can be their environment, not heredity. Therefore the environment affects their intelligence levels differently and hereditary influences affect the similarity in their intelligence levels.