Long-run supply curve depends on the Firm average variable cost (AVC), and without knowledge of AVC, none of the other options can be definitively chosen. So the correct option is D.
The long-run supply curve for a firm is determined by its average variable cost (AVC) at each level of output. To accurately identify the long-run supply curve, we need to know the firm's AVC. Without this information, it's impossible to determine which line segment on the graph reflects the long-run supply curve.
The options A, B, and C all represent different line segments on the graph, but none of them can be definitively chosen as the long-run supply curve without knowledge of the firm's AVC. The long-run supply curve could be anywhere on the graph depending on how AVC changes with different levels of output.
In summary, without information about the firm's AVC, it is not possible to determine which line segment reflects the long-run supply curve.
Complete question :-
Figure 14-9 Suppose a firm operating in a competitive market has the following cost curves: Refer to Figure 14-9. Which line segment best reflects the long-run supply curve for this firm? a. ABCD b. BC c. ABC d. None of the above is correct, We must know the firm's average variable cost.