In an ac circuit $E=E_0\;\sin wt$ and $I=I_0 \sin (wt -\large\frac{\pi}{2})$ the power consumption in circuit is

Question

$(a)\;P=\sqrt 2 E_0 I_0 \\(b)\;P=\large\frac{E_0 I_0}{\sqrt 2}\\ (c)\;P=0 \\ (d)\;P= \large\frac{E_0I_0}{2} $