Circle over London, Buenos Aires, Chicago, Sydney in an airplane or view the cities schema

Circle over London, Buenos Aires, Chicago, Sydney in an airplane or view the cities schematically (图表式的) by means of an urban map and block pan. What is the shape of the city and how does it define itself？ The original container has completely disappeared: the sharp division between city and country no longer exists...One can pick out no definite shapes except those formed by nature: one beholds rather a continuous shapeless mass, here bulging (凸起, 膨胀) or ridged with building, there broken by a patch of green or an unwinding ribbon of concrete... Failing to divide its social chromosomes (染色体) and split up into new cells...the city continues to grow inorganically, indeed cancerously, by a continuous breaking down of old tissues and an overgrowth of formless new tissues. Here the city has absorbed villages and little towns, reducing them to place names ...; there it has, more happily, left the organs of local government and the vestiges (遗迹, 残余) of an independent life, even assisted their revival ...; it has nevertheless enveloped those urban areas in its physical organization and built up the open land that once served to ensure their identity and integrity. Sometimes the expanding street system forms an orderly pattern; sometimes it produces only a crazy network. The difference between one type of order and another is merely a difference in the degree of sprawl, confusion, de-building. As one moves away from the center, the urban growth becomes ever more aimless and discontinuous, more diffuse and unfocused, except where some surviving town has left the original imprint of a more orderly life.

The citys original container appears to have______.

A．enlarged itself

B．disappeared totally

C．decided the city"s present shape

D．marked the limits of the city"s expansion

请帮忙给出正确答案和分析，谢谢！