I am certain the answer is a. It sounds the most correct to me.
Answer:
After the Wright brothers began flying in 1903, mechanics from Europe and the U.S. began experimenting with different designs. World War I was a boon for the pastime of aviation because every country at war realized how important airplanes could be. At first, planes got more stable and durable, but by the end of the war, they were being designed to fight against each other. They had become more maneuverable, could be fixed with mounted guns, and were faster than ever before.
The work of the children was a common custom among peasant and artisan families. In the first decades of the industrial revolution, a large number of boys and girls worked in factories and coal mines. The industrial revolution produced important changes in the lives of millions of people. Many started working in factories and many of them were children. In the first English factories, these children were under the age of seven, forced to work between twelve and fifteen hours every day of the week. They did not eat properly, they were in an environment full of danger and dirt, they could not go to school or play because they spent long hours working.
The government had to spend money for supplies for the military so economic changes for civilians were very real
