The value of x will always be 2. Y can be anything it wants to be and x will still be 2 no matter what, You could pick multiple points on the line for each graph, and only Option 3 will have x always being 2.
Assuming that the population follows an exponential function, the it will take the form: y=a(bˣ) where: a=initial value b=growth factor x=time thus plugging our values in the equation we get: y=40000(1.1ˣ) thus the population in 2011 when t=3 will be: y=40000(1.1³) y=53240
