Final answer:
The domestication of animals during the Neolithic Revolution led to settled societies with surplus resources, which became targets for raiding, thus increasing warfare.
Trade and the establishment of social hierarchies with military elites also contributed to this rise in conflicts.
Therefore, the correct answer is: option "The domestication of animals".
Step-by-step explanation:
The development that could have been a cause for the increase in war after the Neolithic Revolution is the domestication of animals and the related growth in agricultural practices.
This transformation allowed for settled societies, which accumulated resources such as stored grain and domesticated animals, making them targets for raiding by other groups.
The need to protect these resources likely led to more organized and frequent warfare, as well as the emergence of fortified settlements and new social hierarchies with military elites.
As societies became more complex and populations grew, trade activities also emerged, leading to further interaction between different cultures, which sometimes resulted in conflict.
Additionally, social hierarchies and the establishment of property introduced new motivations for war as elites sought to defend or extend their wealth and power. The stronger focus on land ownership and the accumulation of surpluses were significant factors contributing to the increase in warfare during this period.