Consider the lines $L _ { 1 }$ and $L _ { 2 }$ given by\\
$L _ { 1 } : \frac { x - 1 } { 2 } = \frac { y - 3 } { 1 } = \frac { z - 2 } { 2 }$\\
$L _ { 2 } : \frac { x - 2 } { 1 } = \frac { y - 2 } { 2 } = \frac { z - 3 } { 3 }$\\
A line $L _ { 3 }$ having direction ratios $1 , - 1 , - 2$, intersects $L _ { 1 }$ and $L _ { 2 }$ at the points $P$ and $Q$ respectively. Then the length of line segment $P Q$ is\\
(1) $2 \sqrt { 6 }$\\
(2) $3 \sqrt { 2 }$\\
(3) $4 \sqrt { 3 }$\\
(4) 4