The ratio of power which can be transmitted by shaft A to the of shaft B is

Question

Two shafts A and B are made of the same material. The diameter of shaft B is twice that of Shaft A. The ratio of power which can be transmitted by shaft A to the of shaft B is                                             

      (a) 1/2                             (b) 1/4                          (c) 1/8                             (d) 1/16