胎盘由以下哪些结构组成?

A．滑泽绒毛膜+包蜕膜+羊膜

B．滑泽绒毛膜+底蜕膜+真蜕膜

C．叶状绒毛膜+包蜕膜+真蜕膜

D．叶状绒毛膜+底蜕膜+羊膜

E．叶状绒毛膜+真蜕膜+底蜕膜