火电机组稳定负荷AGC性能测试的测试时间应不小于（）。

A.±0.1%
B.±0.2%
C.±0.3%
D.±0.5%

A.5%和90%
B.5%和85%
C.10%和85%
D.10%和90%

A.5min
B.10min
C.15min
D.20min