A long solenoid of radius R, having N turns per unit length carries a time dependent current $$I(t)=I_{0} \sin (\omega t)$$. The magnitude of induced electric field at a distance $$\frac{R}{2}$$ radially from the axis of the solenoid is

A

$$\frac{R}{2} \mu_{o} N I_{o} \omega \cos (\omega t)$$

B

$$\frac{R}{4} \mu_{o} N I_{o} \omega \cos (\omega t)$$

C

$$\frac{R}{2} \mu_{o} N I_{o} \omega \sin (\omega t)$$

D

$$\frac{R}{4} \mu_{o} N I_{o} \omega \sin (\omega t)$$