Bub fizz inc. manufactures chewing gum. through marketing research, it was learned that most of its customers use the chewing gum as mouth freshener. hence, it modified its formula to manufacture gums that have a long-lasting flavor. in this scenario, which of the following was responsible for the change in the product

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.