Most biologists agree that, although they are being eradicated for centuries and remain an endangered and much maligned species, the wolf has made a comeback in some Western states.

they are being eradicated for centuries and remain an endangered and much maligned species
they have been eradicated for centuries, remaining an endangered and much maligned species
it had been eradicated for centuries and it remains an endangered species that had been much maligned
it was eradicated for centuries and remains an endangered and much maligned species
its centuries of eradication, endangerment and being a much maligned species

OA D

My question: The wolf refers to a category of wolves, (more like an adjective) so shouldn't the pronoun be plural rather than singular?

Thanks