Which of the Following Is an Example of a Brand

Which of the following is an example of a brand extension?

A) Tracker, a company selling security systems, advertises its product on a local television network.
B) Dog Handler, a manufacturer of leashes for dogs, collaborates with a competitor to expand its market base.
C) Blossoms, a women's perfume line, advertises its new line through sales promotions and point­of­purchase ^{advertising at department stores.}
D) The manufacturers of Cocoa flakes, a popular cereal, launches a biscuit called "Cocoa crunch" in a new product category.