Which type of waste does domestic sewage specifically include?

Domestic sewage specifically includes a combination of human waste, which encompasses urine and feces, along with the wastewater generated from household activities such as washing, cooking, and bathing. This type of waste is typically a mixture of water and various substances that flow into the sewage system.

While option C mentions household waste, it is important to note that domestic sewage also encompasses the byproducts of daily living in a household context, including soap residues, food particles, and cleaning agents. Groundwater contamination refers to pollutants that may seep into soil and water tables, but it's not a direct component of domestic sewage itself.

The primary focus of domestic sewage is on the wastewater produced directly from human activity in a residential setting, making option C the most representative of what domestic sewage includes. Other options misrepresent the nature of domestic sewage, focusing on specific components or contexts that do not fully capture its definition.