Assume that the short run marginal product curve is a smooth inverted U-shaped curve, when labor input increases, the corresponding total product curve has a(an)
A. U-shape because it will be concave first and then convex later.
B. reverse S-shape because it will be convex first and concave later.
C. S-shape because it will be convex first and concave later.
D. S-shape because it will be concave first and convex later.
E. reverse S-shape because it will be concave first and convex later.