For any real number $x$, let $[ x ]$ be the greatest integer $m$ such that $m \leq x$. Then the number of points of discontinuity of the function $g ( x ) = \left[ x ^ { 2 } - 2 \right]$ on the interval $( - 3,3 )$ is\\
(A) 5\\
(B) 9\\
(C) 13\\
(D) 16 .