B. The water is likely contaminated with high levels of pollution or waste
Answer: Subsistence agriculture.
Explanation: Subsistence agriculture is a type of farming in which farmers cultivate and grow food crops and livestocks to meet their needs and that of their family.
In this type of agriculture, farm products is aimed to survival and it doesn't involve use of large-scale irrigation, chemical fertilizer, or machinery and technology.
C, Proteins is the correct answer
I believe the correct answer among the choices listed above is option A. Parasitism is the kind of interaction that is shown here. Parasitism is a kind of relationship where one feed off the other. Fleas here are referred to as the parasite and the dog is the host.