20. Which of the following statements is correct if the index of refraction of the medium around the optical components changes? The medium is uniform and isotropic.
(A) The wavelength of light in a glass plate changes.
(B) The focal length of a convex mirror changes.
(C) The index of refraction of a lens changes.
(D) The size of a single slit diffraction pattern changes, but that of a double slit does not.
(E) The transmittance of light through a glass plate changes.