The equation that represents the magnetic field of a plane electromagnetic wave which is propagating along the $x$-direction with a wavelength of $10 \,mm$ and a maximum electric field of $60 \,Vm^{-1}$ in the $y$-direction is (where,$c$ is the speed of light):

• A
  $\left(6 \times 10^{-7}\right) \sin [0.2 \pi(c t-x)] \hat{k} \,T$
• B
  $\left(2 \times 10^{-7}\right) \sin [200 \pi(c t-x)] \hat{k} \,T$
• C
  $\left(2 \times 10^{-7}\right) \sin [200 \pi(c t-x)] \hat{i} \,T$
• D
  $\left(6 \times 10^{-7}\right) \sin [0.2 \pi(c t-x)] \hat{i} \,T$