Which of the diagrams correctly portrays the demand (D) and marginal revenue (MR) curves of a pure monopolist that is able to price discriminate by charging each customer his or her maximum willingness to pay?

We calculate the price elasticity of demand as the

A) ratio of the percentage change in the quantity demanded to the percentage change in price. B) change in quantity divided by the change in price. C) ratio of the percentage change in the price to the percentage change in quantity. D) percentage change in the quantity demanded divided by the percentage change in income. E) equilibrium quantity divided by the equilibrium price.

Can a perfectly competitive firm make an economic profit in the short run? Can it incur an economic loss?

What will be an ideal response?