Using a Twin Study,Professor Jones Has Just Found That Identical

Using a twin study,Professor Jones has just found that identical twins were more likely both to develop a conduct disorder than were fraternal twins.He has decided to announce to the world that,clearly,conduct disorder is determined by one's genes.His colleagues suggested,however,that he use caution when interpreting these findings because

A) the environments of identical twins may be more similar than the environments of fraternal twins.
B) parents and other adults may stress the differences between identical twins more than those of fraternal twins.
C) identical twins may be less likely to play with each other than are fraternal twins.
D) identical twins may have a secret language.