The correct answer to this open question is the following.
The impact World War I had on the women who were left home and the men who were in the trenches was devastating in different ways.
First, if men were drafted, they had to leave home to enlist in the military. That was the first shock. Most of them knew they were going to die on the battlefield.
That impacted the family in that women, mothers, had to be in charge of the house, raise children, get a job to feed the family members, knowing that they could never see again their husbands. That should have been a traumatic experience.
Children! How a mother could explain to children that their dad was not going to get back home. Too much pain and suffereing.
Because the rise of merchants weakened the power of monarchs making the peasants leave their manors for towns where they could find work. Also, agriculture stopped being profitable bec merchants imported food so there was no more need for agriculture
Your answer is going to be "All of the Above".
Clara Barton was regarded as the nurse who would later form the American Red Cross. As a nurse her role was more prominent however, she also rode onto the battlefield to and supplied food and water to troops.
Historians look for causes and effects that help to explain how and why events happened.
