dumping garbage in a small part of the forest building a road through the middle of the forest burning dead trees to make smoke in the air preventing too many trees from being cut down
I gave my students this multiple choice question: People can help keep a forest a good place for birds to live by

Only one answer is correct among these 4 choices:
- dumping garbage in a small part of the forest
- building a road through the middle of the forest
- burning dead trees to make smoke in the air
- preventing too many trees from being cut down

Could you tell me which one is correct?

preventing too many trees from being cut down