A cylinder has a radius of 6 feet and a height of 9 feet. Which of the following can be used to calculate the volume of a cone that fits exactly inside the cylinder?
A- 1/3(3.14)(9^2)(6)
B- (3.14)(9^2)(6)
C- 1/3(3.14)(6^2)(9)
D- (3.14)(6^2)(9)