Answer:
Zero barrier, medium barrier, high barrier, very high/ almost impossible entry
Step-by-step explanation:
Refer to exhibit 25-9.
There zero barriers to entry in a perfectly competitive market.
There medium barriers to entry in monopolistic competition.
There high barriers to entry in oligopoly.
There very high or absolute barriers to entry in monopoly.
Perfectly competitive market has zero barrier to entry. Homogenous product are sold in perfectly competitive market.
Monopolistic competition has medium barrier to entry. Differentiated product are sold.
Oligopoly has high barrier to entry where homogenous or differentiated product are sold.
Monopoly has high barrier to entry, that is, almost impossible to enter the market. Unique product are sold.