The correct answer is: A. PRSQ
The Arabs live in tents that can be put up and taken down very easily and quickly, so that they can move from one oasis to another seeking grass and water for their sheep, goats, camels and horses.
- P The Arabs live in tents.
- R These tents can be put up and taken down very easily and quickly.
- S This is so that they can move from one oasis to another.
- Q They do this seeking grass and water for their sheep, goats, camels and horses.
The other options are incorrect because they do not follow the correct sequence of events. For example, in option B, the Arabs are said to move from one oasis to another before they live in tents. This is not possible, as they need tents to live in while they are moving.