Consider the question. The radius of a cylinder is 2 r units and height is 3 r units. Find the curved surface?
Options:
(A) 27
(B) 16
(C) 12
(D) 18
(E) 11
 If the answer is '(C)'; explain the reasoning:

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
2 * π * 2r * 3r = 12 πr2