Photoelectric effect supports quantum nature of light because
(a) there is a minimum frequency of light below which no photo electrons are emitted
(b) the maximum kinetic energy of photo electrons depends only on the frequency of light and not on its intensity
(c ) even when the metal surface is faintly illuminated, the photo electrons leave the surface immediately
(d) electric charge of the photo electrons is quantised

Options

A. There is minimum frequency of light below which no photoelectrons are emitted.
B. The minimum `K.E.` of photoelectrons depends only on the frequency of light and not on its intensity.
C. Even the metal surface is faintly illuminated by light of wavelength less than the threshold wavelength, the photoelectrons leave the surface immediately.
D. Electric charge of photoelectrons is quantized.

Explanation

Existence of cut-off frequency and photoemission takes place even when intensity is low.