Let $G$ (respectively, $H$ ) be a Sylow 2-subgroup (respectively, Sylow 7-subgroup) of the symmetric group $S _ { 17 }$. Pick the correct statement(s) from below.\\
(A) The order of $G$ is $2 ^ { 15 }$.\\
(B) $H$ is abelian.\\
(C) $G$ has a subgroup isomorphic to $\mathbb { Z } / 8 \mathbb { Z } \times \mathbb { Z } / 8 \mathbb { Z }$.\\
(D) If $\sigma \in S _ { 17 }$ has order 4 , then $\sigma$ is a 4-cycle.