Step 1: Parametrize the equations.
For the first line, the direction ratios are \( (1, 2, -12) \), and for the second line, the direction ratios are \( (1, 1, 6) \).
Step 2: Use the formula for the shortest distance.
The formula for the shortest distance between two skew lines is:
\[
d = \frac{|(\vec{a_2} - \vec{a_1}) \cdot (\vec{d_1} \times \vec{d_2})|}{|\vec{d_1} \times \vec{d_2}|}
\]
By substituting the values of direction ratios, we calculate the shortest distance to be \( 2 \) units.
Step 3: Conclusion.
The correct answer is (C) 2 units.