Why did amundsen survive the return trip while Scott died?

The rations allocated for the Scott crew were inadequate and nutritionally lacking, while Amundsen's contained the necessary B and C vitamins. Scott used ponies for hauling, while Amundsen used the more adaptable dogs. Amundsen's team had adequate fuel allocation, due to planning, that allowed them to melt ice to drink, while Scott had a shortage of fuel that did not allow them to melt ice into water, and thus suffered from dehydration.