Which function rule matches the graph below?
Af(x) = x^2
Bf(x) = 4x^2
Cf(x) = x^2 + 4
Df(x) = x^2 - 4
Af(x) = x^2
Bf(x) = 4x^2
Cf(x) = x^2 + 4
Df(x) = x^2 - 4