The verb is is because it "is" the plant.
The brainstorming is a technique used to generate several ideas to solve a problem, is free thinking environment that gain power on the participants when they start linking one idea to idea to the other in a spontaneously stimulating creativity of the and after that the ideas are evaluated. Considering the mechanism and purpose or this method from the option given it would be useful for the situation when your teacher asks for a list of possible topics and when you’re creating an outline for your paper.
The answer to the question is a. Packed.
A few other ways to reduce pollution could be to reduce the use of single-used plastics like water bottles, straws and utensils. To recycle properly, as it helps keeps plastic out of the ocean.
Organizing Cleanup campaigns and spreading the word, for example to help remove plastic from a local beach.
To support bans, or the adoption of them in your community. There's many municipalities where there's plastic bags bans or straw bans for example.
We should avoid products containing microbeads (tiny plastic particles), we can find them on face scrubs, toothpastes and bodywashes.
Lastly, we could definitely support organization that address these situations such as Oceanic Society, 5 Gyres, Algalita, etc
Hope this helps!