The best option from the list would that "<span>C. Factories employed more people, including women and children, for lower wages and longer hours," since the supply of labor was so great. </span>
Technology.
World War 1 was the first war in an industrialized age. New weapons and vehicles were used in this war that had never been used before. With the invention of the plane in 1901 led the way for the plane to be used as a gun ship, light bomber, and heavy bomber.
True; the early color photos were more vibrant, though not by intention
