A product line is a group of products that are physically similar or are intended for a similar market. Which of the following is the best example of a product line?

a. Sony offers DVD players, televisions, computers and video games.
b. Hyundai produces ocean-going vessels, plants and machinery, automobiles, steel and electronic products.
c. Coca-Cola produces Coca-Cola, Diet Coke, Sprite and Fanta.
d. United Technologies produces elevators, furnaces and helicopters.