30. A three-phase 318.75kVA, 2300V alternator has an armature resistance of 0.35 Ω phase and a synchronous reactance of 1.2 Ω phase . Please determine the voltage regulation at full-load kVA, 0.5 power factor leading, and rated voltage. (A) 1.55% (B) 3.22% (C) 6.12% (D) -5.11%