What is the exit point for a firm in the long run, and why is it significant?

The exit point is where price equals average fixed cost, and it is significant because the firm covers all fixed costs.

The exit point is where price equals average total cost, and it is significant because below this point, the firm will exit the market.

The exit point is where price equals marginal cost, and it is significant because the firm maximizes profit.

The exit point is where price equals average variable cost, and it is significant because the firm will cease production.