Determine whether the lines $l_1$ and $l_2$ are parallel, coincident, skew, or intersecting. If they intersect, find the point of intersection:
$l_1: \frac{x-2}{1} = \frac{y+1}{2} = \frac{z-1}{3}$
$l_2: \frac{x-5}{3} = \frac{y-1}{2} = \frac{z-4}{1}$
Coincident
Intersect at (1, 3, 1)
Parallel but not coincident
Intersect at (-1, 3, 2)
Skew
None of the above.