If Genes Alone Contribute to a Trait, Which of the Following

If genes alone contribute to a trait, which of the following patterns of correlations would be observed?

A) 1.00 for identical twins raised together but a lower correlation for those raised apart
B) 1.00 for both identical and fraternal twin pairs raised together but a lower correlation for those pairs raised apart
C) 1.00 for identical twins and .50 for fraternal twins raised together and raised apart
D) No significant correlation between identical twins or fraternal twins, regardless of whether they are raised together or apart