Which of the following was not a factor that improved health in the late nineteenth century?
a. improved diet and nutrition
b. better housing
c. child labor
d. improved clothing

Because without physical activity, the body has extra "energy" if you will, and so when it is time for bed you are not tired, so you end up staying up all night. also there is probably an effect on your internal clock, which messes with your melatonin production which goes hand in hand with your sleep cycle

Answerfarmer's market; (b) would be my second choice