If the mirror image of the point \( P(3, 4, 9) \) in the line \( \dfrac{x-1}{3} = \dfrac{y+1}{2} = \dfrac{z-2}{1} \) is \( (\alpha,\beta,\gamma) \), then \( 14(\alpha + \beta + \gamma) \) is:
\( 138 \)
\( 132 \)
\( 102 \)
\( 108 \)