Answer:
Country B, because due to their environmental impact, they are at the greatest disadvantage. For country A there are other food sources besides crops, such as trade with other countries. Country C can build up rather then expanding out more, and there are other resources to build with other than wood like stone and metal. Country D can use clean sources of energy like solar, rather than oil. Besides, they don't even know there is oil, they just think they know it's there.