With No~1 and No~2 alternators running in parallel and the KW loads equally shared, one alternator is drawing much higher current than the other.What does this indicate?（）

A. The alternators are not generating the same voltages and should be adjusted on automatic voltage regulator rheostats
B. Alternator frequencies are different and should be adjusted on the governor speed controllers
C. Alternators are out of phase and should be tripped and paralleled again
D. One alternator has lost one of its phase