The reason why it's ”b” is because of the formula for the volume of a cylinder, which is πr^2*h.
Diameter is just 2 times the radius so the equation should look like this: π3^2*10
Simplifying into terms of pi, the equation should read 90Ď€.
Multiplying 90 by pi to the first two decimal places, it should be around the same answer as option ”b”.
