Question: The aboriginal people ended up being displaced by settlers who justified themselves with the fact that the displaced people didn't have a formal system to do what?

Choices: 
- fight back
- spend time
- own home
- talk to each other
- own land

The rationale to choose "own land" as the answer is that: 

own land people ended up being displaced by settlers who justified themselves with the fact that the displaced people didn't have a formal system to do what?