The statement that best describes an informal argument for the formula for the volume of a cylinder is:
A cylinder is a stack of h circles, each with an area of πr² and a thickness of one unit, so its volume formula is V=πr²h.
This statement effectively conveys the idea that the volume of a cylinder can be understood by considering it as a series of circular cross-sections stacked on top of one another, where each cross-section has an area of πr² and contributes to the overall volume based on its height, h.