In an electromagnetic wave in free space the root mean square value of the electric field is $E_{rms}=6\text{V/m}$. The peak value of the magnetic field is:

1. A
   $1.41\times 10^{-8}\text{T}$
2. B
   $2.83\times 10^{-8}\text{T}$
3. C
   $0.70\times 10^{-8}\text{T}$
4. D
   $4.23\times 10^{-8}\text{T}$