Which wildlife conservation subscription model pioneered the 'adopt an animal' concept that has since been replicated by organizations worldwide?

Conservation organizations increasingly rely on subscription models to fund their efforts. These recurring donation programs offer various benefits to supporters while providing predictable revenue streams for wildlife protection. This poll tests your knowledge about one of the most successful wildlife subscription programs that revolutionized how conservation organizations engage with donors and create sustainable funding models.

This is a live public trivia poll on AIPolls.Net. Vote and see real-time results.

WWF's Species Adoption Program (launched 1973)
National Wildlife Federation's Animal Guardians (launched 1981)
The Nature Conservancy's Species Stewardship (launched 1977)
Defenders of Wildlife's Animal Sponsorship (launched 1985)