What is the volume of a cylinder? Give an informal argument for the formula.

A) V = πr2h; A cylinder has a circle base and top; the middle can be unwrapped to a rectangle.

B) V = πr2h; A cylinder is like a stack of circles, so it's the area of the circles times the height.

C) V = 2πr2 + 2πrh; A cylinder has a circle base and top; the middle can be unwrapped to a rectangle.

D) V = 2πr2 + 2πrh; A cylinder is like a stack of circles, so it's the area of the circles times the height.