Which one of the following is not a method of in situ conservation of biodiversity?

The approach of in situ conservation is the protection of threatened species in their natural habitat. Such methods of conservation include biosphere reserves, national parks, wildlife sanctuaries and sacred groves. Conservation of species in a special setting away from their natural habitat is called ex situ conservation. These include zoological parks, botanical gardens, wildlife safari parks, cryopreservation, etc.