Moses led them out of Egypt and through the desert. His general, Joshua, then took over.
Answer:
Mein Kampf (Disclaimer, do NOT read it it's literally a garbage political book that has anti-semitic things)
Explanation:
I believe the answer would be the last option. A resource has value, and people are willing to pay for it most likely because the resource is scarce. When a resource is not enough or the supply is low as compared to its demand, then most likely that price or value of it would increase.
It was an example of preparedness