By definition, parallel lines have the same slope, in which they have no point of intersection. Therefore, they will have no solution (making them an inconsistent system).
Out of all the given options, the inequality statements in Option C has the same slope of 1 (regardless of the inequality symbol, what matters is their lack of point of intersection because their lines are parallel).
Therefore, the correct answer is Option C: y ≥ x + 1; y ≤ x - 1.
I would suggest graphing this in order to find your solution however. Graph (-2,5) on a graph, then go up four units and over to the right one. Keep going until you find your point (-1,9).
7-4