Monopolies can charge prices well above the supply curve, and even above equilibrium price. Why don't other producers enter the market when prices are above equilibrium?

1.The price will fall to equilibrium, making profits unattainable.

2.The monopolizing company will cut prices to drive out new competition.

3.There are barriers to entry that make it virtually impossible to enter the market.

4.It will be more difficult to establish a strong customer base.