The diagram below represents a perfectly competitive industry (market) and four possible individual firm-level response graphs (Graph A, Graph B, Graph C, and Graph D). Initially, both the market and the firm are in long-run equilibrium.

Which of the firm-level graphs (Graph A, Graph B, Graph C, or Graph D) correctly illustrates the short-run response of an individual profit-maximising firm to the market shift shown in the Market Diagram?