Why does light of a certain frequency need to be used to produce a current in the photoelectric effect? a. the frequency of light must be the same as the frequency of vibration of the atoms in the substance to cause a current. b. the atoms can only lose their electrons when they are provided with packages of energy of a certain discrete amount. c. the atoms of the substance require specific frequencies of light to cause them to vibrate. d. only light of certain frequencies can penetrate the substance to a sufficient depth to cause the atoms to react.