Water polution is caused by a: agricultural runoff b: sewage c: heavy metals d: all of the above

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.