As shown in the figure,a point charge $Q$ is placed at the centre of a conducting spherical shell of inner radius $a$ and outer radius $b$. The electric field due to charge $Q$ in three different regions $I$,$II$,and $III$ is given by: $(I: r < a, II: a < r < b, III: r > b)$

• A
  $E_{I} = 0, E_{II} = 0, E_{III} \neq 0$
• B
  $E_{I} \neq 0, E_{II} = 0, E_{III} \neq 0$
• C
  $E_{I} \neq 0, E_{II} = 0, E_{III} = 0$
• D
  $E_{I} = 0, E_{II} = 0, E_{III} = 0$