Consider an (almost) perfectly competitive market: the only difference is that different firms have different cost curves (no two firms have the same cost curve). Suppose firm A is in the market in the long-run equilibrium and making zero profit. Suppose there the demand curve shifts to the right. In the new long-run equilibrium,

A. Firm A makes strictly positive profits.

B. Firm A exits the market.

C. Firm A makes zero profits.

D. Firm A has higher costs than every other firm in the market.