If $f(x) = 4x+4$, for what value of $a$ is it true for $4f(a) =f(2a)$ ?

Question

$\begin{array}{1 1} (a)\; \frac{3}{2} \\ (b)\; -\frac{3}{2} \\ (c)\; \frac{2}{3} \\ (d)\; -\frac{2}{3} \end{array}$