New technology lead to more destructive weapons (mustard gas and machine guns) during world war i
these new weapons lead to
a prolonged war and greatly increased the number of casualties in the war
a reduction in the number of casualties in the war
a faster end to the war because soldiers refused to fight with such deadly warfare
a reduction in the spending cost for each nation in the war

A prolonged war and greatly increased the number of casualties in the war

Explanation:

In World War I we saw the introduction of chemical weapons, machine guns, artillery, and tanks. All of this resulted in trench warfare and the lack of tactics to fight the new weapons meant that the war would be longer and a lot deadlier than it would have been without those weapons. It dragged for years from one stalemate to another and claimed a lot of lives.