The answer is D. It held Germany (and Austria) responsible for the war and required reparations
Early humans eventually formed hunter-gatherer societies so catching food and cooking it could be split evenly between the people, and so everyone could get food properly, all the while sharing with eachother and looking out for eachother. Being in groups made it easier to catch more food, because they could take out more than they could together than with only one person. Forming these societies made things much more easy and efficient for them.
At the time, more than 750,000 people were displaced and this caused a big refugee crisis due to the fact that the Palestinians were expelled from their homes and a lot of villages were left vacant.