increase in fossil fuel production decrease in corn production increase in severe weather decrease in nutrients in soil
I gave my students this multiple choice question: Corn can be used to make ethanol, which is a fuel for some cars. What problem could be caused by the increased use of ethanol?

Only one answer is correct among these 4 choices:
- increase in fossil fuel production
- decrease in corn production
- increase in severe weather
- decrease in nutrients in soil

Could you tell me which one is correct?

decrease in nutrients in soil