Which of the following shows the particle nature of light?

When yellow light is incident on a surface,no electrons are emitted,while green light can emit them. If red light is incident on the surface,then:

The number of photoelectrons emitted for light of a frequency $\nu$ (higher than the threshold frequency $\nu_0$) is proportional to

The time taken by a photoelectron to come out after the photon strikes is approximately

Threshold frequency for a metal is $15 \times 10^{14} \, Hz$. The light of wavelength $6000 \, \text{Å}$ falls on the metal surface. Then photoelectrons [velocity of light in air, $c = 3 \times 10^8 \, m/s$]:

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: