An electron (mass $9\times 10^{-31}\text{kg}$ and charge $1.6\times 10^{-19}\text{C}$) moving with speed $c/100$ ($c$ = speed of light) is injected into a magnetic field $\vec{B}$ of magnitude $9\times 10^{-4}\text{T}$ perpendicular to its direction of motion. We wish to apply a uniform electric field $\vec{E}$ together with the magnetic field so that the electron does not deflect from its path. Then (speed of light $c=3\times 10^8{\text{ms}}^{-1}$):

1. A
   $\vec{E}$ is perpendicular to $\vec{B}$ and its magnitude is $27\times 10^4{\text{V m}}^{-1}$
2. B
   $\vec{E}$ is perpendicular to $\vec{B}$ and its magnitude is $27\times 10^2{\text{V m}}^{-1}$
3. C
   $\vec{E}$ is parallel to $\vec{B}$ and its magnitude is $27\times 10^2{\text{V m}}^{-1}$
4. D
   $\vec{E}$ is parallel to $\vec{B}$ and its magnitude is $27\times 10^4{\text{V m}}^{-1}$