The charge on a parallel plate capacitor is varying as $q=q_{o} \sin 2 \pi n t .$ the plates are very large and close together. Neglecting the edge effects, the displacement current through the capacitor is
(a) $\frac{q}{\varepsilon_{n} A}$
(b) $\frac{q_{o}}{\varepsilon_{o}} \sin 2 \pi n t$
(c) $2 \pi n q_{o} \cos 2 \pi n t$
(d) $\frac{2 \pi n q_{o}}{\varepsilon_{o}} \cos 2 \pi n t$