A New Variety of Doritos Is Initially Introduced in Some

A new variety of Doritos is initially introduced in some areas of New South Wales, Victoria and Tasmania.After its initial success, Smith's markets the Doritos in those entire states, then in Queensland, and finally the entire country.Smith's is using a __________ for its new variety of Doritos.

A) multi-stage introduction
B) rollout approach
C) test-market expansion
D) mass commercialisation
E) trickle-down approach