500kV变压器、电抗器施加电压前变压器油微水含量不大于（）。

A.20L/L
B.15L/L
C.10L/L
D.8L/L

A.20L/L
B.15L/L
C.10L/L
D.8L/L

A.40kV/2.5mm
B.50kV/2.5mm
C.60kV/2.5mm
D.70kV/2.5mm