For a given surface area of a closed right circular cylinder, the volume is maximum when the height is:

For a given surface area of a closed right circular cylinder, the volume is maximum when the height is:

• A. Equal to its radius
• B. Equal to its diameter
• C. Twice its diameter
• D. Half of its radius

Answer: B) Equal to its diameter

Explanation: This is a standard optimization result. For a cylinder with fixed surface area to have maximum volume, its height must equal its base diameter (h = 2r).