Answer:
The correct answer is Layer B!
Explanation:
The magnetic field is generated by electric currents due to the motion of convection currents of molten iron in the Earth's outer core
Pretty sure its c. From the text you provided me
I would have to go with Sewage mostly because it smells and because it can really hurt the environment. Plants can die and it just is gross to smell. So this would definitely pollute the earth. I hope this helped! :D