I sent an email to state ed about this question. They had me contact their Geometry scoring team. I was told they only received a couple other calls on this question. The claim is the best answer is 4 based on the locus of two intersecting lines. There is nothing stating the paths are lines nor is there anythign that says the paths couldn't be segments and have common end points either. If anyone else has issues with this question then please contact them directly.