The variation of the magnitude of the electric field with radial distance $r$ due to a given configuration is depicted in the accompanying figure. The configuration could be

• Correct answer
  A

  thick spherical conducting shell with a point charge at its centre.
• B

  thick spherical dielectric shell with a point charge at its centre.
• C

  conducting sphere with surface charge.
• D

  two neutral concentric thin conducting shells with a point charge at the centre.

Hence, the correct answer is option: 'A'.