Final answer:
City dwellers faced overcrowded living conditions, lack of sanitation and clean water, and the spread of infectious diseases.
Step-by-step explanation:
City dwellers in the past faced several problems, including overcrowded living conditions, lack of sanitation and clean water, and the spread of infectious diseases. In cities, many people lived in cramped tenement houses or apartments with poor ventilation and substandard plumbing and sanitation.
This led to the rampant spread of diseases like typhoid and cholera. Lack of clean water and proper sanitation measures further worsened the health conditions of city dwellers. Therefore, the correct answer is d. All of the above.