A torsional system with discs of moment of inertia I₁ and I₂ as shown in the below figure, is gear driven such that the ratio of speed of shaft B to shaft A is 'G'. Neglecting the inertia of gears, the equivalent inertia of disc on shaft B at the speed of shaft A is equal to

A. G.I₂

B. G².I₂

C. I₂/G

D. I₂/G²

Please do not use chat terms. Example: avoid using "grt" instead of "great".