已知正弦电压u=311sin(314t-π/6)有一正弦电流I=7.07sin(314t+π/3),它们之间的相位差为( )
A.电压滞后电流π/2
B.电压超前电流π/2
C.电压滞后电流π/6
D.电压超前电流π/6
正确答案是A