Hint: Plants are photosynthetic eukaryotic organisms that consist of a cell wall made up of cellulose and make their food by the process of photosynthesis. Animals are multicellular eukaryotic organisms that consume organic material and breathe Oxygen to survive which depends upon plant and various plant materials for their food.
Plants and animals are best protected in national parks. The parks which are used for conservation purposes and are created for the protection of animals and plants are known as national parks. They are a reserve of natural or semi-natural developed land of a sovereign state that is declared or owned. Individual nations designate their national parks which serve as conservation of wild nature for posterity and a symbol of national pride. National parks have increased tourism over time and are perceived as a brand name that is associated with nature-based tourism and symbolizes a high-quality natural environment that consists of well-designed tourist infrastructure. A park ranger supervises the management of the conservation and use of the park resources. They have fire fighting responsibilities and can rescue or search for a mission.
Sanctuaries: An area where the habitats of the animal habitats and their surroundings are conserved and protected from any kind of disturbance while the activities including the capturing, killing, and poaching of animals are strictly prohibited in these areas. These areas provide comfortable living to the animals and are mainly made to educate humans as to how to treat the animals. People are not allowed to unescort there and tourists are not permitted. Sanctuaries provide care to animals and to allow them to live peacefully in their natural habitats. It includes large rivers, dense forests, high and beautiful mountains.
Botanical gardens: These are the gardens that allow the cultivation and preservation of a wide range of plants. They are reserved with labeled tags with their botanical names. It is a collection of many species of plants such as succulent plants, garden herbs, and many more exotic plants. Visitors include educational displays, art exhibitions,s and open-air theatre musical performances with tours and other entertainments. They are controlled by the universities or scientific research organizations that associate herbaria and research programs in the botanical sciences
Zoo: They are an animal park within enclosures that display to the public and replicate their natural habitats for behavioural patterns which benefit the animals and visitors. Special climatic conditions are created for the animals and the walkthrough exhibits are there for visitors for non-aggressive species. Visitors are how to avoid eating foods that animals might snatch or to keep their paths away.
So, the correct answer is '(d) National park'.
Note: 84 million acres of wild landscapes are protected by the National parks and the Yellowstone National Park in Montana is the oldest National park which was founded in 1872. Yosemite National Park in California is one of the third highest waterfalls among 10 in the world.