The potential at a point x (measured in $\mathrm{\mu }$m) due to some charges situated on the x-axis is given by $\mathrm{V}\left(\mathrm{x}\right)=20/\left({\mathrm{x}}^2-4\right)$volt.
The electric field E at x = 4 $\mathrm{\mu }$m is given by:
 

• A

  5/3 volt/$\mathrm{\mu }$m and in the +ve x direction.

• B

  10/9 volt/$\mathrm{\mu }$m and in the -ve x direction.

• C

  10/9 volt/$\mathrm{\mu }$m and in the +ve x direction.

• D

  5/3 volt/$\mathrm{\mu }$m and in the -ve x direction.