Which of the Following Is True of Product Differentiation

Multiple Choice

Which of the following is true of product differentiation?

A) Product differentiation ensures that firms face a horizontal market demand curve.
B) Product differentiation allows monopolistically competitive firms to make positive economic profits in the long run.
C) Prices of differentiated products have to vary substantially for product differentiation to be successful.
D) Successful product differentiation can be based on differences that are perceived by consumers.