As business increased, and the city grew with rapid strides, the necessities of the poor became the opportunity of their wealthier neighbors, and the stamp was set upon the old houses, suddenly become valuable, which the best thought and effort of a later age have vainly struggled to efface. Their "large rooms were partitioned into several smaller ones, without regard to light or ventilation, the rate of rent being lower in proportion to space or height from the street; and they soon became filled from cellar to garret with a class of tenantry living from hand to mouth, loose in morals, improvident in habits, degraded, and squalid as beggary itself." It was thus the dark bedroom, prolific of untold depravities, came into the world. Which development most likely contributed to the conditions described by Riis?

A.
The organization of labor unions among new immigrant groups in cities

B.
The rise in immigration quotas for Eastern European nations

C.
High wages paid to immigrant children working in factories

D.
The imposition of scientific management on unskilled immigrant workers