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.

Cities develop as a result of functions that they can perform. Some functions result directly from the ingenuity of  the  citizenry,  but  most  functions  result  from  the  needs  of  the  local  area  and  of  the surrounding hinterland (theregion that supplies goods to the city and to which the city furnishes services and  other  goods).  Geographers  often  make  a  distinction  between  the  situation  and  the  site  of  a  city. Situation  refers  to  the  general  position  in  relation  to  the  surrounding  region,  whereas  site  involves physical  characteristics  of  the  specific  location.  Situation  is  normally  much  more  important  to  the continuing  prosperity  of  a  city.  If  a  city  is  well  situated  in  regard  to  its hinterland,  its  development  is much  more  likely  to  continue.  Chicago,  for  example,  possesses  an  almost  unparalleled  situation:  it  is located at the southern end of a huge lake that forces east-west transportation lines to be compressed into its vicinity, and at a meeting of significant land and water transport routes. It also overlooks what is one of the world’s finest large farming regions. These factors ensured that Chicago would become a great city regardless  of  the disadvantageous characteristics  of  the available  site,  such  as  being  prone  to  flooding during thunderstorm activity.

Similarly,  it  can  be  argued  that  much  of  New  York  City’s  importance  stems  from  its  early  and continuing advantage of situation. Philadelphia and Boston both originated at about the same time as New York  and  shared  New  York’s  location  at  the  western  end  of  one  of  the  world’s  most  important  oceanic trade  routes,  but  only  New  York  possesses  an  easy-access  functional  connection  (the  Hudson-Mohawk lowland)  to  the  vast  Midwestern  hinterland.  This  account  does  not  alone  explain  New  York’s  primacy, but  it  does  include  several  important  factors.  Among  the  many  aspects  of  situation  that  help  to  explain why  some  cities  grow  and  others  do  not,  original  location  on  a  navigable  waterway  seems  particularly applicable.  Of  course,  such  characteristic  as  slope  drainage,  power  resources,  river  crossings,  coastal shapes, and other physical characteristics help to dertermine city location, but such factors are normally more significant in early stages of city development than later.

What does the passage mainly discuss?

• A. 
  The development of trade routes through United States cities
• B. 
  Contrasts in settlement patterns in United States
• C. 
  Historical differences among three large United States cities
• D. 
  The importance of geographical situation in the growth of United States cities