Let $f$ be a differentiable function such that $f ( 1 ) = 2$ and $f ^ { \prime } ( x ) = f ( x )$ for all $x \in R$. If $h ( x ) = f ( f ( x ) )$, then $h ^ { \prime } ( 1 )$ is equal to :\\
(1) $4 e ^ { 2 }$\\
(2) $2 e$\\
(3) $4 e$\\
(4) $2 e ^ { 2 }$