Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 28 to 34.

In  1900  the  United  States  had  only  three  cities  with  more  than  a  million  residents-New  York, Chicago,  and  Philadelphia.  By  1930,  it  had  ten  giant  metropolises.  The  newer  ones  experienced remarkable  growth,  which  reflected  basic  changes  in  the  economy.  The  population  of  Los  Angeles (114,000 in 1900) rose spectacularly in the early decades of the twentieth century, increasing a dramatic 1,400 percent from 1900 to 1930.
A  number  of  circumstances  contributed  to  the meteoric  rise  of  Los  Angeles.  The  agricultural potential  of  the  area  was  enormous  if  water  for  irrigation  could  be  found,  and  the  city  founders  had  the vision and dating to obtain it by constructing a 225-mile aqueduct, completed in 1913, to tap the water of the Owens River. The city had a superb natural harbor, as well as excellent rail connections. The climate made  it  possible  to  shoot  motion  pictures  year-round;  hence  Hollywood  not  only  supplied  jobs  but  also disseminated an image of the good life in Southern California on screens all across the nation. The most important  single  industry  powering  the  growth  of  Los  Angeles,  however,  was  directly  linked  to  the automobile.  The  demand  for  petroleum  to  fuel  gasoline  engines  led  to  the  opening  of  the  Southern California oil fields, and made Los Angeles North America’s greatest refining center.
Los  Angeles  was  a  product  of  the  auto  age  in  another  sense  as  well:  its  distinctive  spatial organization depended on widespread private ownership of automobiles. Los Angeles was a decentralized metropolis, sprawling across the desert landscape over an area of 400 square miles.
It was a city without a real center. The downtown business district did not grow apace with the city as  a  whole,  and  the  rapid  transit  system  designed  to  link  the  center  with  outlying  areas  withered  away from  disuse.b Approximately  800,000  cars  were  registered  in  Los  Angeles  County  in  1930,  one  per  2.7 residents. Some visitors from the east coast were dismayed at the endless urban sprawl and dismissed Los Angeles as a mere collection of suburbs in search of a city. But the freedom and mobility of a city built on wheels attracted floods of migrants to the city.

What is the passage mainly about?

• A. 
  The growth of cities in the United States in the early 1900s
• B. 
  The development of the Southern California oil fields
• C. 
   Factors contributing to the growth of Los Angeles
• D. 
  Industry and city planning in Los Angeles