The answer is (D), all of the above.
Choice A says agricultural runoff; this can include pesticides, insecticides, and other chemicals that harm people’s health if they drink water that is contaminated.
Choice B says sewage, and of course, if sewage (which includes feces and urination) touches water, it counts as a sort of pollution.
Finally, choice C says heavy metal. Lead, one example, can pollute water, as shown by the Flint, Michigan water crisis.
Therefore, the answer is all of the choices.