I think the answer is C - both pieces of info are needed to figure it out.
1- insufficient on its own because the info doesn't indicate in which directions each slope points. We do know, however, that they intersect, so one slop must point down and one must slope up. The one that slopes down is the one that is less, but from this info we can't tell which is n and which is p.
2 - insufficient on its own because although the y intercepts are different, the slopes could be pointing in any direction (up or down) or any degree of up or down. Even though n is located higher up on the y axis, it could be pointing down with a negative slope.
1 + 2 - together this info indicates which slope is higher and which is lower. If n intersects the y axis at a higher point than where the p line intersects this axis, and if both lines must meet at (5,1), then the n slope must be lower than the p slope. Either the n slope is pointing downwards towards (5,1) while p is pointing upwards towards (5,1), or the n slope is pointing slightly less upward toward (5,1) in comparison to the p slope
We are able to answer the question, so the answer is C.
