In the following question, two columns are given, containing three phrases each. A phrase from the first column may or may not connect with a phrase from the second column to make a grammatically and contextually correct sentence. There are five options, four of which display the sequence(s) in which the phrases can be joined to form a correct sentence. If none of the phrases make a correct sentence, mark ‘None of these’ as your answer.

Column (1)	Column (2)
(A) Placental mammals develop within	(D) a placental mammal to the mother's blood supply.
(B) The placenta connects the embryo of	(E) the mother's womb and are nourished by a placenta.
(C) Marsupials lack a placenta and are born at an earlier stage in their	(F) development than placental mammals.