In which of the following circumstances are competitive pressures associated with the bargaining power of buyers relatively moderate-to-weak? Select one: a. Apple designs and manufactures its chip processors rather than buying them from Intel. b. Consumers can easily compare different smartphones' features over the Internet before buying them. c. Buyers tend to delay purchases of luxury goods, such as home entertainment systems, until they are on sale. d. The supply of soccer balls increases during the World Cup season. e. Dairy products are usually standardized and therefore differentiated only by price.