The rational function f is defined by f(x)=x+ba and the partial graph of y=f(x) is shown. If h(x)=f(2x), which equation defines h?
h(x) = 3 / (x + 2)
h(x) = 6 / (x + 8)
h(x) = 12 / (x + 4)
h(x) = 6 / (2x + 8)
