Voltage and current in the a.c circuit are given by $V= 5 \sin (100 \pi t -\large\frac{\pi}{6})$ and $I= 4 \sin (100 \pi t + \pi/6)$

Question

$(a)\;\text { Voltage leads, the current by $30^{\circ}$} \\(b)\;\text{Current leads the voltage by $30^{\circ}$ } \\ (c)\;\text { Voltage leads the voltage by $60^{\circ}$} \\ (d)\;\text {Current leads the voltage by $60^{\circ}$ } $