What is the exact volume of the cylinder?

a. 32 in^3

b.64 in^3

c. 128 in^3

d. 512 in^3

Volume of the cylinder=area (circle) x height
area (circle)=πr²
r=radius=4 in.
area=π(4 in)²=16π in²
height=8 in

Volume of the cylinder=(16π in²)(8 in)=128π in³≈402.12 in³

Answer=  128π in³        or        402.12 in³

Maybe the answer is 20mm. all i really did was just multiply, which is obvious.