Answer:
D : biosphere
Step-by-step explanation:
The biosphere is the part of the Earth where all the organisms live and it contains all the ecosystems found in the planet. The biosphere extends to any place where there is life. According to this, we are part of the biosphere.
The other options are not right because the hydrosphere refers to all the water on the planet, the atmosphere is the layer around the planet that contains gases and the lithosphere is the solid outer part of the Earth.