The answer to your question is going to be d
Answer:
improving air quality :
1. keep it clean. a clean house may be a healthier house , because good indoor hygiene can greatly cut down on dust and animal dander
2. keep the greenery outdoors
3. change your filters
4. invest in an air purifier
5. let fresh air in
Answer:Colonization
Explanation: They are setting stuff up for their own gain in not already established states
