Which of the following statements about 'Multiple Pregnancies' is TRUE?

Twin peak or Lambda sign is seen in dichorionic diamniotic twin gestation. In this the chorion and amnion for each twin reflect away from the fused placenta to form an inter twine membrane. A space that exist in the intewine membrane is filled by proliferating placental villi giving rise to twin peak sign. Twin peak sign appear as a triangle with the base at the chorionic surface and apex in the inter twin membrane. Ref: Textbook of Obstetrics By Dutta, 6th Edition, Page 207; Ultrasound in Obstetrics and Gynecology By Meyz, 2004, Page 422, 423; Ultrasound and Multifetal Pregnancy, 1998, Pages 74, 75, 73; Textbook of Perinatal Medicien By Kurjak, 2nd Edition, Page 499, 500, 501.