One Reason to Be Cautious About Attributing the Assessed Personality

One reason to be cautious about attributing the assessed personality similarities of separately raised identical twins to shared genes is that

A) home environments have less impact on personality than does peer pressure.
B) many separately raised identical twins were reunited prior to assessing their personalities.
C) epigenetic marks have a strong impact on personality development.
D) adopted children's personalities are highly similar to those of their adoptive parents.