Here's a problem to solve: Ethanol is an alternative fuel made from corn. What is one of the unfavorable effects of using ethanol as a fuel?

Among the 4 following options, which is the correct answer?

- A: decreased cost of fuel production
 
- B: decrease in farm land available for food production
 
- C: increase in the consumption of fossil fuels
 
- D: increased carbon footprint from driving automobiles
 