Part A represents the solution to the system.
You can choose a point in the region to verify the region.
For example, the point (0, 2) is in Part A only.
Substitute it into the original inequalities and both statements are true.
x = 0 and y = 2
2 ≥ 0 + 1 → 2 ≥ 1 TRUE
2 + 0 ≥ -1 → 2 ≥ -1 TRUE