They are invertebrates because they have no bones
Region I think
Sorry if wrong
The answer is A.
This is because cities contain more people in one area, thus they contain more businesses like restaurants, cafes, etc. that produce more overall exhaust than say a more rural town with fewer people. Light pollution will also be largely greater over a city as opposed to a rural town.
The water flowing in a stream or river is fed by numerous smaller streams, which are fed by even smaller streams that collect water from melting snow or ice up in the mountains, from springs, and possibly from human wasterwater sources. The bottoms of rivers are also below the water table in many places, so there will always be water at that level.
