For the ellipse $C : \frac { x ^ { 2 } } { a ^ { 2 } } + \frac { y ^ { 2 } } { b ^ { 2 } } = 1 ( a > b > 0 )$, let $A$ be the left vertex. Points $P$ and $Q$ are both on $C$ and symmetric about the $y$-axis. If the product of the slopes of $AP$ and $AQ$ is $\frac { 1 } { 4 }$, then the eccentricity of $C$ is:\\
A. $\frac { \sqrt { 3 } } { 2 }$\\
B. $\frac { \sqrt { 2 } } { 2 }$\\
C. $\frac { 1 } { 2 }$\\
D. $\frac { 1 } { 3 }$