Answer:
Nuclear.
Explanation:
This is a trick question, but you have to listen to the wording! They say, non-renewable source. So, lets go through the choices:
Geothermal - renewable, great for the enviroment, uses water and steam from earth's core.
Hydropower - renewable, uses water in hydroelectric dams.
Nuclear - Non-renewable, although still causes pollution.
Solar power - renewable, based on the sun and its energy, uses solar panels.
All of those choices, besides nuclear, come from renewable sources! So, the only choice left is nuclear, although bad for the enviroment, the right answer.
If your still having trouble or I got this incorrect, I will comment back just mabye not for a while, sorry.