Arrange the following in correct sequence to attain equilibrium under perfect competition.

(A) LRMC start rising.

(B) Both LRAC and LRMC fall.

(C) Both LRAC and LRMC rises.

(D) LRMC cuts LRAC from below.

Option 1 -> Incorrect sequence, doesn't follow the natural progression of cost curves.

Option 2 -> Incorrect sequence, starts with LRMC rising which is not the initial phase.

Option 3 -> Correct sequence: (B) Both curves fall initially → (A) LRMC starts rising → (D) LRMC cuts LRAC from below at minimum point → (C) Both curves rise.

Option 4 -> Incorrect sequence, starts with both curves rising which contradicts the initial economies of scale phase.

Hence, Option 3: (B), (A), (D), (C) -> In perfect competition, long-run equilibrium is achieved at the minimum point of LRAC. The sequence follows: First, both LRAC and LRMC fall due to economies of scale (B). Then, LRMC starts rising while LRAC continues to fall (A). Next, LRMC intersects LRAC from below at its minimum point - this is the equilibrium point where Price = LRMC = minimum LRAC (D). Finally, both curves rise due to diseconomies of scale (C). This intersection point represents the optimal production scale for the firm. -> correct