The correct option is C Sanctuaries
Human activities have deleterious effects on ecosystem.
Ecosystems can be conserved by creating national parks and sanctuaries.
Niche is the ecological role, an organism plays in an ecosystem. Biomes are large geographical areas spread in different continents but they share the same climatic conditions, animals and plants.
Biosphere is the sum of total ecosystem or the zone of life for plants, animals and microbes on the Earth's crust.