Someone plz explain how to do this question?

Skew means that they are not intersecting and not parallel.
1) Not this one (A), because AB || GH, you can draw the plane through these two segments and the are going to be parallel in that plane.
2) Not this one (C), because AB || CD, you can draw the plane through these two segments and the are going to be parallel in that plane.
3) Not (D) because AC and CG are intersecting.

So the answer, is B.

The answer is B since all the answers in B are skewed to line AB.