Answer:
c. Some Americans thought World War I could lead to improved health care in the United States.
Step-by-step explanation:
The passage discusses how the experience of World War I highlighted the importance of maintaining high standards of health for national efficiency. It mentions that soldiers returning from the army have received sanitary training and will demand health protection from civil authorities equal to what they received in the military. This suggests that the experience of the war led some Americans to believe that there would be increased activity for the betterment of public health and improved health care in the United States.