Which best describes the price element of the marketing mix?
a. Southwest Airlines allows customers to choose a higher fare for a flight so that it is refundable if needed.
b. Many popular new songs are available for purchase and digital download via Apple's iTunes Store.
c. Progressive Insurance uses a spokescharacter named Flo for many of its television commercials.
d. Delta offers a variety of plumbing fixtures fit for use in residential or commercial properties.