decreasing soil fertility decreasing oil transportation increasing the greenhouse effect increasing carbon dioxide emissions
I am hesitating between 4 options to answer the following question, which option should I choose?
Question: Corn is widely being used in the United States to make ethanol for use in automobile fuel. How might the overproduction of corn negatively affect the environment?
Possibilities:
- decreasing soil fertility
- decreasing oil transportation
- increasing the greenhouse effect
- increasing carbon dioxide emissions

decreasing soil fertility