单项选择题

交流电压v(t)=Vmsin(314t+60°),交流电流i(t)=Imsin(314t-30°),则v(t)与i(t)相位为()

A.v(t)超前i(t)90°
B.v(t)超前i(t)30°
C.v(t)与i(t)同相
D.v(t)超前i(t)60°