A, B and C are three large sheets having charge densities $+3\mathrm{\sigma }\mathrm{C}/{\mathrm{m}}^2,-\mathrm{\sigma }\mathrm{C}/{\mathrm{m}}^2$ and $+2\mathrm{\sigma }\mathrm{C}/{\mathrm{m}}^2$ respectively. Then electric field at P is 

• A

  zero 

• B

  $-\frac{\sigma }{2{\in }_0}\widehat{i}$

• C

  $\frac{3\sigma }{2{\in }_0}\widehat{i}$

• D

  $\frac{\sigma }{{\in }_0}\widehat{i}$