What Would Be the Most Effective Way to Differentiate Genetic

What would be the most effective way to differentiate genetic and environmental effects on personality?

A) Study twin pairs,some of whom were raised together and some of whom were raised apart.
B) Study monozygotic twins who were raised in the same family and who have never been apart.
C) Study dizygotic twins who were raised in the same family and who have never been apart.
D) Study non-twin siblings who were raised together,sharing the same family environment.