Which of the following is not a method of ex-situ conservation ?

In ex-situ conservation, threatened animals and plants are taken out from their natural habitat and placed in special setting where they can be protected and given special care. Zoological parks, botanical gardens, in-vitro fertilisation, micropropagation and cryopreservation serve this purpose.
National parks are an example of in-situ conservation. In-situ conservation is the process of protecting organisms in their natural habitat.
Biosphere reserves, national parks, sanctuaries and sacred groves are a part of in-situ conservation.