If the shortest distance between the lines \( \frac{x-1}{2}=\frac{y-2}{3}=\frac{z-3}{\lambda} \) and \( \frac{x-2}{1}=\frac{y-4}{4}=\frac{z-5}{5} \) is \( \frac{1}{\sqrt{3}} \), then the sum of all possible values of \( \lambda \) is:
\( 16 \)
\( 6 \)
\( 12 \)
\( 15 \)
