Which of the following is false about twin pregnancy

A、Its occurrence is related to genetic factors;

B、Dizygotic twins have two layers of chorion and two layers of amniotic membrane between the two placentas;

C、Monozygotic twins have only two layers of amniotic membrane between the two placentas;

D、Monozygotic twins can coexist in one amniotic cavity;

E、Conjoined twins are formed from monozygotic twins