<u>Given</u>:
Let x represents the radius of the cylinder.
Given that the height of the cylinder is twice the radius of its base.
The height of the cylinder is 2x.
We need to determine the volume of the cylinder.
<u>Volume of the cylinder:</u>
The volume of the cylinder can be determined using the formula,
Substituting r = x and h = 2x, we get;
Simplifying, we get;
Thus, the expression that represents the volume of the cylinder is 2πx³ cubic units.
Hence, Option b is the correct answer.