Which of the following does not support the wave nature of light?

In a photoelectric experiment,increasing the intensity of incident light :

Define threshold frequency and on which factor does threshold frequency depend?

In a photoelectric effect experiment,light of frequency $1.5$ times the threshold frequency is made to fall on the surface of a photosensitive material. If the frequency is halved and the intensity is doubled,the number of photoelectrons emitted will be:

Given below are two statements: one is labelled as Assertion $A$ and the other is labelled as Reason $R$.
Assertion $A :$ In photoelectric effect,on increasing the intensity of incident light,the stopping potential increases.
Reason $R :$ Increase in intensity of light increases the rate of photoelectrons emitted,provided the frequency of incident light is greater than threshold frequency.
In the light of the above statements,choose the correct answer from the options given below:

The figure shows a plot of photo current versus anode potential for a photo sensitive surface for three different radiations. Which one of the following is a correct statement?