The correct answer for this question would be C) At seafloor spreading centers or the third option.
Answer:
Researchers need a lot of data to monitor a species population because the environment is very diverse in types of species found at different places .
What happens to one part of it could affect the population of other animals, humans, and may also effect the ecosystem of that certain environmental region .
I would say D. small intestine
If you want an explanation, here it is
After leaving the stomach, water is absorbed mostly in the early segments of the
small intestine, the duodenum, and the jejunum. A small portion of all water absorption occurs in the stomach and the colon: the small intestine absorbs 6.5L/day, whereas the colon absorbs 1.3L/day.