$R = 6 \: cm = 0.06 \: m, r= 3\: cm =0.03 \: m$
$C = 100 \: pF = 100 \times 10^{-12}F$
$V = 230\: V$
$\omega = 300 \: rad/s$
rms value of conduction current,$ I = \large\frac{V}{X_c}$
$X_c =$ Capacitive resistance = $ \large\frac{1}{\omega C} $
So, I = V × ωC.
$= 230 \times 300 \times 100 \times 10^{-12}$
$= 6.9 \times 10^{-6} A = 6.9\: \mu A$
Magnetic field is $B = \large\frac{\mu_or I_o}{2\pi R^2}$
where,$ I_o$ = maximum value of current = $ \sqrt{2} I$
$=\large\frac{ 4\pi \times 10^{-7} \times 0.03 \times \sqrt2 \times 6.9 \times 10^{-6}}{ 2\pi \times (0.06)^2 }$
$= 1.63 \times 10^{-11}T$
Ans : (c)