If the distance of the point \( (a, 2, 5) \) from the image of the point \( (1, 2, 7) \) in the line \( \frac{x}{1} = \frac{y-1}{1} = \frac{z-2}{2} \) is \( 4 \), then the sum of all possible value of \( a \) is equal to:
\( 11 \)
\( 9 \)
\( 6 \)
\( 4 \)