Can you answer this question on dielectrics?

Consider a spherical cavity in an infinite, homogeneous and isotropic dielectric material of permittivity epsilon. When placed in an external electric field E, the electric field inside the cavity is

a) 3.epsilon.E/(2.epsilon+epsilon0)

b) (2.epsilon+epsilon0)E/3.epsilon

c) -epsilon.E

d) E/epsilon

Epsilon0 means epsilon in free space

Please derive the answer for me.