A naturally occurring sanctuary, such as an island, which protects species from getting hunted, predated or poached is called as a wildlife refuge. It is also known as a wildlife sanctuary. Whereas, a park in use for conservation purposes is known as a National park. These are methods of in-situ biodiversity conservation. In-situ conservation of biodiversity is done by conserving the species in their natural habitats. It is the best way of biodiversity conservation.
So, the correct answer is 'Conservation of wildlife'.