Answer:
Atmosphere.
Step-by-step explanation:
Earth is the only planet where the environmental conditions are favorable to support life. Different layers of the earth are atmosphere, geosphere, biosphere and hydrosphere.
Atmosphere surround the earth like the blanket and protect the organisms from the harmful sun rays. Atmosphere is the envelope of all the gases that surrounds the earth. Atmosphere is important for the maintenance of life on the planet earth.
Thus, the correct answer is option (B).