Answer:
(D) The common conditions faced by child laborers in the early 20th century.
Explanation:
Since the Industrial Revolution, the increase in production has made the demand for labor increase greatly. There were no labor regulations, so the workday was very long and child labor was exploited. This can be traced back to the twentieth century, as in the illustration, in which children appear on a factory floor in work coats and tired faces.
However, during the course of the twentieth century, workers began to organize and to demand improvements in working conditions. In this scenario, the exploitation of child labor has been prohibited and now it's considered a crime.