The function f on the set of real numbers is defined for every real number x as
$$f ( x ) = \left\{ \begin{array} { c c }
x + 2 , & x < 0 \\
x , & x \geq 0
\end{array} \right.$$
Accordingly, what is the value of the sum $\sum _ { k = - 3 } ^ { 4 } f ( k )$?\\
A) 8\\
B) 10\\
C) 12\\
D) 14\\
E) 16