The correct option is D Rural-urban migration and high unemployment led to the growth of urban slums in England.
The Industrial Revolution in Britain witnessed a massive surge in the number of people migrating to cities in search of jobs. As the housing infrastructure in these cities were inadequate to meet the demand from the influx of migrants, it led to the growth of slums. These slums lacked proper sanitation and ventilation facilities and became a hotbed for diseases. However, things improved in the 19th century when the government imposed several public health acts.