Please help me with this word problem

Answer:
B
Step-by-step explanation:
Formula- [tex]2*\pi * radius\\[/tex]
First, to find the radius u divide 9 by 2 and get 4.5.
Next, you multiply 2 and 3.14 and get 6.28.
Finally, You multiply 4.5 and 6.28 together to get 28.26.
Sorry if this is confusing, this was how I was taught to find the circumference of a circle.