Which one of the following is an example of ex-situ conservation?

Ex‑situ conservation refers to the preservation of components of biological diversity outside their natural habitats. This approach involves maintaining and breeding species in artificial or controlled environments such as captive facilities.

Among the given options, zoos and botanical gardens fit this definition because they keep animals and plants in locations that are not their original wild ecosystems, providing managed care, breeding programs, and educational displays.

The other choices—wildlife sanctuaries, protected areas, and national parks—are all examples of in‑situ conservation, where species are protected within their natural habitats.