A light source illuminates a metal plate. The frequency of the light is greater than the threshold frequency of the metal so we see the emission of photoelectrons. What do we observe if the intensity of the light is decreased? Select all that apply.

A) the photoemission rate decreases.
B) the photoemission rate increases.
C) the speed of the photoelectrons and the photoemission rate decrease.
D) the speed of the photoelectrons decreases.
E) none of the above