Correct option: (d) X is a National Park, Y is a sanctuary and Z is a Biosphere Reserve.
Biosphere reserves are multipurpose protected areas, its function is to restore, conserve, and develop the natural ecosystem.
The biosphere reserve is the area for the betterment of wildlife where human activities including forestry, grazing, or cultivation are allowed.
National park is an area reserve for wildlife where they live for a long time in a natural environment.
The natural parks are under the control of the central government which does not allow grazing or agriculture practices in such areas.
The wildlife sanctuaries are the conservation areas for animals in supportable environments.