The correct option is
C Let's discuss all the options one by one:
Option (a).
In this graph, population of United States decreased with time, which is not the given scenario.
Option (b).
In this graph, population increases with time, but again it starts decreasing, which is not the given scenario.
Option(c).
In this graph, population of United States always increases with time.
Hence, This best represents the given scenario.
(d).
In this graph, population increases with time, but again it starts decreasing, which is not the given scenario.
Hence, option (c) is the correct choice.