which of the following are characteristics of a perfectly competitive market? check all apply

• significant barriers to entry
• in the short run, positive economic profit possible
• in the long run firms operate at the minimum of the ATC curve
• in the long run positive economic profit possible
• in the short run only zero economic profit possible
• in the long run only zero economic profit possible
• easy entry/exit
• MR=MC at the profit maximizing quantity
• P=MC at the profit maximizing quantity
• P>MC at the profit maximizing quantity
• P