The expression for the capacity of the capacitor formed by compound dielectric placed between the plates of a parallel plate capacitor as shown in the figure,will be (area of plate $= A$)

• A
  $\frac{{\varepsilon _0}A}{{\left( {\frac{{{d_1}}}{{{K_1}}} + \frac{{{d_2}}}{{{K_2}}} + \frac{{{d_3}}}{{{K_3}}}} \right)}}$
• B
  $\frac{{\varepsilon _0}A}{{\left( {\frac{{{d_1} + {d_2} + {d_3}}}{{{K_1} + {K_2} + {K_3}}}} \right)}}$
• C
  $\frac{{\varepsilon _0}A({K_1}{K_2}{K_3})}{{{d_1}{d_2}{d_3}}}$
• D
  ${\varepsilon _0}\left( {\frac{{A{K_1}}}{{{d_1}}} + \frac{{A{K_2}}}{{{d_2}}} + \frac{{A{K_3}}}{{{d_3}}}} \right)$