The Following Figure Shows the Long-Run Average Cost Curve of a Firm

Multiple Choice

The following figure shows the long-run average cost curve of a firm.
Figure 6-1

-Refer to Figure 6-1. The production function of the firm displays increasing returns to scale at all levels of output between _____.

A) A to E
B) C to D
C) D to E
D) A to C
E) B to E