What is the main idea of the passage?
A.
The modern cities won't be places to live the good life so much as way stations.
B.
Aristotle's idea about urban life is no longer applicable in the 21st century.
C.
Locational factors will not be so important in the 21st century as in Aristotle's time.
D.
There will be no fixed buildings in the future and the culture of architecture will change.