A single-phase, 300 kVA, 11 kV/2.2 kV, 60 Hz transformer has the following equivalent circuit parameters referred to the high voltage side: (a) 57.6 kΩ, 16.34 kΩ (b) 2.74, 8.45 (c) If the load impedance on the low-voltage side is 10 Ω, 60°, the voltage regulation using the approximate equivalent circuit is?

Options:
A) 5.0%
B) 7.5%
C) 10.0%
D) 12.5%