None of them.
A parasite is defined as:
Just because the embryo is metabolically dependant does not make it a parasite as it is of the same species.
Another part of the terminology, a parasite invades from outside, it is not of the same species, and makes direct contact with the host, not through an umbilical cord attached to a placenta created by the organism itself to nourish in the body its offspring. The placenta is created within the body by the host to encourage and enable the offspring to nourish itself, the umbilical is created by the embryo during development, this symbiotic relationship is not indicative of a parasitical invasion.
Anyway, it doesn't meet the definition as the embryo is of the same species and could not therefore ever meet the definition of a parasite.