A charged particle of mass $5\times {10}^{-5}\mathrm{kg}$ is held stationary in space by placing it in an electric field of strength ${10}^7{\mathrm{NC}}^{-1}$ directed vertically downwards. The charge on the particle is

• A

  $-20\times {10}^{-5}\mathrm{\mu C}$

• B

  $-5\times {10}^{-5}\mathrm{\mu C}$

• C

  $5\times {10}^{-5}\mathrm{\mu C}$

• D

  $20\times {10}^{-5}\mathrm{\mu C}$