Choose the best answer to complete

New york city , which has a population of nearly 9 million , is one of the densest cities in the world .1 ........... It has the world's largest subway system , trafific can still be quite bad , particularly at rush hour . The city decided that it would be a good idea to encourage more people to use bicycles . If more people rode bicycles , the roads would be less 2............ with cars . also , when you ride a bicycle , you are exercising ,which makes you healthy . but how can you encourage people to ride more bikes ?
the city came up with an innovative solution .in 2013 ,city workers began installing long racks of bicycles in differnent neighborhoods .these bicycles were , for a small fee , availiable 3..............anyone to use . A person could ride the bicycles from one bike rack to 4.............. mike rack and park it there . this system was ideal for people 5............ did not own bikes and wanted to take a bicycle on a short ride with out having to return it to the place they took it from . this also made it possible to move quickly between areas that did not connect easily by the subway .
1 A . although                                  B , beause                  c . howerver                 d so
2 .A empty                                       b   stuck                      c . free                          d sparce
3. A to                                              B with                          C for                             D . By
4. A some                                        B all                             C other                         D another
5. A who                                          B whose                       C which                       D where