The correct option is
C A, B and C
Conservation of biodiversity has become a global concern since the rate of biodiversity loss in recent times has become high. Bioresources of all kinds need to be conserved not only for their services to mankind and the ecosystem but also for their own intrinsic value as living beings.
Conservation of biodiversity can be done using two distinct strategies as follows like in situ (on site) and ex situ (off site).
The approach of conserving threatened and endangered species of plants and animals by taking them out of their natural habitat and protecting and caring for them in a special and controlled environment is known as ex situ conservation.
Zoological parks, botanical gardens and wildlife safari are set up to serve off site conservation. Ex situ conservation is done when urgent measures are required for conserving a species. Hence option c is correct.
Botanical gardens are meant for the conservation of endangered or threatened flora. These are provided with seed banks and tissue culture labs which help in conservation and propagation of such plant species. The botanical gardens also have provision for research for improvement of plant varieties.
Figure : Botanical garden
Zoological parks are one of the most popular ex situ strategies for conservation of animals or fauna where various animals are kept within enclosures, demonstrated to the public, and can be used for the study.
Figure : Zoological park
In safaris, the animals are free to wander within fenced enclosures and visitors are taken around the park in a vehicle.
In situ conservation of biodiversity is a strategy that is based on the belief that if an organism needs to be conserved, it should be conserved with its entire ecosystem. Thus in situ conservation of biodiversity is done in protected areas such as wildlife sanctuaries, national parks, biosphere reserves and sacred groves.
A biosphere reserve is a multipurpose protected area of habitat in which man is an integral part of the system. These are highly protected sites selected by UNESCO. Hence option a, b and d are incorrect.
Figure : Biosphere reserve