Zoro Inc., a consumer electronics company, does not store any of its materials in the warehouse. Instead, the company's procurement department orders small quantities of materials as and when they are required. The vendors supply the ordered material directly to the company's manufacturing unit a day or two before the production starts. This arrangement helps Zoro Inc. to reduce costs and boost efficiency. This scenario best illustrates .

Which of the following statements is (are) true? i. free entry to a perfectly competitive industry results in the industry's firms earning zero economic profit in the long run, except for the most efficient producers, who may earn economic rent. ii. in a perfectly competitive market, long-run equilibrium is characterized by lmc < p < latc. iii. if a competitive industry is in long-run equilibrium, a decrease in demand causes firms to earn negative profit because the market price will fall below average total cost.