Jack developed a toothpaste using only natural ingredients, and he has been quite successful selling the product in health food stores and some grocery stores. He has recently developed a toothbrush using bamboo and natural components. Jack is considering a $\_\_\_\_\_\_\_\_,$ giving the toothbrush the same brand name as the toothpaste in order to create greater brand awareness.

Question $9$Select one:

A$.$

joint brand

B$.$

premium brand

C$.$

brand extension

D$.$

co$-$brand

E$.$

natural brand