Wildlife sanctuary is region where the animals are kept in the protected region away from the practices like, predation and competition. It is a protected area, a geographic territory within which wildlife is protected. Such wildlife refuges are generally officially designated territories.
A national park is a park in use for conservation purposes. Often it is a reserve of natural, semi-natural, or developed land that a state declares or owns. National parks are almost always open to visitors. Most national parks provide outdoor recreation and camping opportunities as well as classes designed to educate the public on the importance of conservation and the natural wonders of the land in which the national park is located.
Zoological garden is the park in which animal are conserved in man made habitat.
Botanical garden is the region which have varieties of plant species maintained in a man-made habitat.
Thus, the correct answer is option C.