The range of values that the function
$$f ( x ) = \frac { x ^ { 2 } + 2 x + 4 } { 2 x ^ { 2 } + 4 x + 9 }$$
takes as $x$ varies over all real numbers in the domain of $f$ is:\\
(A) $\frac { 3 } { 7 } < f ( x ) \leq \frac { 1 } { 2 }$\\
(B) $\frac { 3 } { 7 } \leq f ( x ) < \frac { 1 } { 2 }$\\
(C) $\frac { 3 } { 7 } < f ( x ) \leq \frac { 4 } { 9 }$\\
(D) $\frac { 3 } { 7 } \leq f ( x ) \leq \frac { 1 } { 2 }$