Staple foods vary from place to place, but typically they are inexpensive or readily available foods that supply one or more of the three organic macronutrients needed for survival and health: carbohydrates, proteins, and fats. Typical examples of staples include tuber- or root-crops, grains, legumes, and other seeds.
I feel as if B helps explain the conflict more. Whereas the other answers are just details or add ons in the short story. Also the other answers seem more external than B.
