For the rotor system as shown in Fig.92, the mass required for its complete balancing is

(a) \(1.5 \mathrm{~kg}\) at \(2 \mathrm{~m}\) radius and at \(225^{\circ}\) from reference

(b) \(3 \mathrm{~kg}\) at \(1 \mathrm{~m}\) radius and at \(45^{\circ}\) from reference

(c) \(8 \mathrm{~kg}\) at \(1 \mathrm{~m}\) radius and at \(225^{\circ}\) from reference

(d) \(4 \mathrm{~kg}\) at \(2 \mathrm{~m}\) radius and at \(45^{\circ}\) from reference.