Hello!
The answer you were looking for is....
(D) Nonpoint source pollution is difficult to regulate, because its source is difficult to track.
Answer:
Louis Pasteur was the scientist who confirm that bacteria and other microorganisms is the reason for variety of diseases.
Answer: They are all formed from the same elements.
D. Earthquakes, volcanoes, and hot springs release energy from Earth's interior.
Without knowing the main subject it is related to beside just Biology,
Biotic and Abiotic factors
Basically
Living and non-living factors
Hope this helps