一道简单的不等式数学题（英文好的进!）

一道简单的不等式数学题（英文好的进!）
4.The region of the xy plane that satisfies y > x^2 or y > 0 is
(A) a circle
(B) a square
(C) the region of the plane bounded by a parabola
(D) a crescent-shaped region in the plane
(E) the half of the plane above the x-axis
请说明为什么.