Three rods each of length L and mass M are placed along X, Y and Z-axes in such a way that one end of each of the rod is at the origin. The moment of inertia of this system about Z axis is
(a) 2ML2/3
(b) 4 ML2/3
(c) 5 ML2/3
(d) ML2/3
Ans. a
(12)