Product differentiation is a hallmark of monopolistic competition, and the text lists four sources of such differentiation: physical differences, prestige, location, and service. How do firms in the industries listed here differentiate their products? How important is each of the four sources of differentiation in each case? Give the most important source of differentiation in each case.

• fast-food restaurants.
• espresso shops/carts.
• hair stylists.
• soft drinks.
• wine