Dunkin Donuts sells coffee and donuts in thousands of stores across the United States and abroad. Which of the following could be a distinctive competency of Dunkin Donuts?

a. Dunkin Donuts has a large number of stores across the country

b. Dunkin Donuts is able to lower its costs by purchasing coffee in greater bulk than anyone else

c. Dunkin Donuts makes their own donuts fresh every day

d. Dunkin Donuts sells coffee in a variety of flavors