I would say D it seem to be the likely choice but not a 100%
It is also possible to move substances across membranes against their concentration gradient (from areas of low concentration to areas of high concentration). ... If the energy of ATP is directly used to pump molecules against their concentration gradient, the transport is called primary active transport.
Hope this helps
Answer:
1.) A factory produces chemical waste and releases it into a water system
2.) Water becomes polluted in nearby rivers and streams
3.) Aquatic plants stop thriving
4.) Small fish do not have adequate food
5. Larger fish have less prey to eat and their numbers decline