D because they were handmade reset
The correct answer is - trade.
The Sumerians engaged in trade with their move of exchanging their surplus food for materials like the copper that they needed to develop their weapons and thus their army forces. This was a very smart move from their side because they managed to use the resource they had in abundance but was scarce in the other surrounding areas so that they take what they need to become stronger and pretty much defend more efficiently from the same people they were engaging in trade with.
The ming dynasty used a civil service exam to select officials, while the yuan dynasty banned chinese people from participating in government.
The treaty prevented the war because <span>The treaty moved the Line of Demarcation 800 miles further west. This gave Portugal more opportunity to claim lands unexplored by other Europeans.
While the portugals were exploring those land, the spain could obtain the resource from the conflicted territories without having to face the threat of the Portuguese's army.</span>
