The correct answer is C. Zoo.
In situ conservation efforts are those that take place in the natural habitat of the species being conserved. National parks, sanctuaries, and biosphere reserves are all examples of in situ conservation efforts. Zoos, on the other hand, are not in situ conservation efforts because they keep animals in captivity.
National parks are large areas of land that are protected by the government. They are often home to a variety of plant and animal species. Sanctuaries are similar to national parks, but they are specifically designated for the protection of a particular species or group of species. Biosphere reserves are large areas of land that are managed for both conservation and sustainable development. They are often home to a variety of plant and animal species, as well as human communities.
Zoos are facilities that keep animals in captivity for educational and entertainment purposes. While zoos can play a role in conservation by breeding endangered species and educating the public about conservation, they are not considered to be in situ conservation efforts.