Final answer:
Waterborne diseases like cholera and typhoid that resulted in countless deaths due to the mixing of waste water with drinking water sources were caused by fecal contamination. The correct option is C.
Step-by-step explanation:
The diseases that originated from the mixing of wastewater with drinking water resources are caused by fecal matter contaminating the water supply. This fecal contamination results in waterborne diseases such as cholera and typhoid, which are spread through the feces of infected individuals.
Urban factories and slaughterhouses exacerbating the situation by dumping waste directly into water sources without proper treatment, thereby enabling the spread of pathogens that lead to countless deaths due to these diseases.
Notably, during the industrial era, the lack of sanitation, open sewers, and contaminated water supplies made poor living conditions a fatal reality for many, leading to outbreaks of these diseases.
Hence, Option C is correct.