A clown is exhibiting a magic trick on the streets wherein he rotates a bucket in a vertical plane without allowing the water in it to spill out. Here, clearly the clown uses centrifugal force to balance the weight of water. This will be possible when,

(A) the bucket has r.p.m. = \(\sqrt{\frac{400g}{\pi^2R}}\)

(B) the bucket has maximum speed = \(\sqrt{2gR }\)

(C) the bucket has r.p.m. = \(\sqrt{\frac{900\,g}{\pi^2\,R}}\)

(D) the bucket has r.p.m = \(\sqrt{\frac{3600\,g}{\pi^2R}}\)