Consider the Following Short- Run Cost Curves for a Profit-

Consider the following short- run cost curves for a profit- maximizing firm in a perfectly competitive industry.
FIGURE 9- 2
-Refer to Figure 9- 2.The short- run supply curve for this perfectly competitive firm is its

A) ATC curve at and above $3.
B) marginal cost curve at and above $1.50.
C) entire marginal cost curve.
D) marginal cost curve at and above $3.
E) AVC curve at and above $1.50.