A parallel plate capacitor made to circular plates each of radius $R=6 \mathrm{~cm}$ has capacitance $C=100 \mathrm{pF}$. The capacitance is connected to a $230 \mathrm{~V}$ AC supply with an angular frequency of $300 \mathrm{rad} / \mathrm{s}$. The rms value of conduction current will be
(A) $5.7 \mu \mathrm{A}$
(B) $6.3 \mu \mathrm{A}$
(C) $9.6 \mu \mathrm{A}$
(D) $6.9 \mu \mathrm{A}$