What is the purpose of a check sheet?

A. To organize data on the frequency and sequence of occurrence of defects in order to identify patterns, relationships and possible immediate remedies
B. To develop a checklist of activities that are necessary to prevent defects, prior to beginning an operation or process
C. To check on the health of a process using sampling

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.