To convey the idea that a group's status in society can be reversed over time.
Answer: Option A.
Step-by-step explanation:
In the passage that has been given above, it is shown that the society never remains the same through out. If it is of one type at present, it might change totally and reverse after some time.
In the passage, the group which was homogeneous at one time, had same houses, received same salary and had same style of living got changed after some years. They got distinguishable and diversified showing the society does not remain the same forever.