Answer:
Maintains Biodiversity: A and D
Increase Biodiversity: B and C
Step-by-step explanation:
"Aug 23, 2019 — Biodiversity is a term used to describe the enormous variety of life on Earth. It can be used more specifically to refer to all of the species in one region or ecosystem. Biodiversity refers to every living thing, including plants, bacteria, animals, and humans."
~National Geographic Society
i make this note because it explains this point in a way that is understandable, with this, we can see why planting more trees -making more room and suitable habitat for animals- could maintain (or possibly increase) biodiversity where as dumping sewage water -killing a lot of marine life due to chemicals in the sewage or trash such as plastic items- would decrease it
hope this helps you out :)