Answer: D
Assume that the previous radius was \(r\), now it is \(2r\).
The previous height was \(h\), now it is \(2h\).
The current volume is \(V\), and the previous volume was \(v\).
\(\therefore\) \(\cfrac{V}{v}=\cfrac{\cfrac{1}{3}\pi (2r)^2.2h}{\cfrac{1}{3}\pi (r)^2.h}=\cfrac{8r^2h}{r^2h}=\cfrac{8}{1}\)
\(\therefore\) \(V=8\times v\)
Assume that the previous radius was \(r\), now it is \(2r\).
The previous height was \(h\), now it is \(2h\).
The current volume is \(V\), and the previous volume was \(v\).
\(\therefore\) \(\cfrac{V}{v}=\cfrac{\cfrac{1}{3}\pi (2r)^2.2h}{\cfrac{1}{3}\pi (r)^2.h}=\cfrac{8r^2h}{r^2h}=\cfrac{8}{1}\)
\(\therefore\) \(V=8\times v\)