Which Statement Is True Regarding Conjoined Twins

Multiple Choice

Which statement is true regarding conjoined twins?

A) Splitting of the inner cell mass may have occurred before gastrulation.
B) Surgical separation is nearly impossible even with minor fusion.
C) Separation of the blastomeres early in cleavage may have occurred.
D) Splitting of the blastomeres or of the embryonic disc is not complete.
E) Two separate oocytes are fertilized at the same time.