Argument made in the text: “We…are facing a future of limited geographic mobility which will have social and economic consequences”.
1 – Correct
The third sentence suggests that as climate change increases, flooding will also increase. So 1 is assumed.
2 – Correct
The last sentence suggests that we will face a future with less geographic mobility. This sentence assumes that no action will be taken to prevent flooding.
3 – Correct
The second sentence suggests that no one will buy homes which are built in flooded areas. So this assumes that people will not want to move to areas which are at risk of flooding.
All statements are correct, so E is the answer.