Which of the Following Lifestyle Changes Would Have the Greatest

Which of the following lifestyle changes would have the greatest impact on reducing an individuals environmental impact?

A) Reducing your meat consumption to once or twice a week.
B) Buying a more fuel efficient vehicle and only using it when you are taking long trips instead of traveling locally.
C) Downsizing and moving into a smaller house.
D) Reducing the number of children in your household to reach a zero population growth rate.
E) Waiting until later in life to have children and only have one per couple.