Read the following passage and choose the option (A, B, C or D) that best answer each of the questions below.
The five most populated cities today are Tokyo (35 million people), Mexico City (19 million), New York (18.5 million), Bombay (18.3 million) and Sao Paulo (18.3 million). In 1950 only Tokyo and New York had populations of more than 10 million people. By 2050 there will be 22 cities of that size. The United Nations' report concludes, "The current population picture is one of dynamic population changes, reflected in new and diverse patterns of childbearing, mortality, migration, urbanization and ageing. The continuation and consequences of these population trends present opportunities as well as challenges for all societies in the twenty-first century."
