Answer: C) One foot every day
When bamboo grows in the early Spring or Summer they are the fastest growing plants in the world. Some species of bamboo can grow between a foot and a foot and a half for an entire month. After that "it then branches out and finally leafs out. Once completing its growth it will never grow again." Bamboo's ability to grow extraordinarily quickly is one of the factors that make it so desirable as a green material for floors, chairs, etc.
Source: Jade Mountain Bamboo