What is the volume of a sphere with a surface area of ​ 16π ​ft²?

We need to find the radius...

The surface area is given by :      4 pi * r^2

So

16 pi  =  4 pi * r^2     divide both sides by pi

16  = 4r^2     divide both sides by 4

4  = r^2       take the positive root

2  ft  = r

So...the volume of a sphere is

(4/3) pi ( radius)^3  =

(4/3) pi (2) ^3

(4/3) pi * 8

(32/3) pi   ft^3   ≈   10.66 pi  ft^3

None of the given answers are correct  !!!