The solution set of the shaded area above is

• A.Y ≥ 0, y ≥ x and y + x ≤ 4
• B.Y ≤ x, y + x ≤ 4
• C.Y + x ≥ 4, y ≤ x
• D.Y ≤ x, y + x ≤ 4 and y ≥ 0
• E.