Which one of the following is true in photoelectric emission?

By increasing the intensity of incident light, keeping the frequency $(v > v_0)$ fixed on the surface of a metal:

The minimum energy required to remove an electron from the surface of a metal is called:

Assertion $(A) :-$ The photoelectrons produced by a monochromatic light beam incident on a metal surface have a spread in their kinetic energies.
Reason $(R) :-$ The work function of the metal varies as a function of depth from the surface.

Two metallic plates $A$ and $B$,each of area $5 \times 10^{-4} \, m^2$,are placed parallel to each other at a separation of $1 \, cm$. Plate $B$ carries a positive charge of $33.7 \, pC$. $A$ monochromatic beam of light,with photons of energy $5 \, eV$ each,starts falling on plate $A$ at $t = 0$,so that $10^{16}$ photons fall on it per square meter per second. Assume that one photoelectron is emitted for every $10^6$ incident photons. Also assume that all the emitted photoelectrons are collected by plate $B$ and the work function of plate $A$ remains constant at $2 \, eV$. The electric field between the plates at the end of $10 \, seconds$ is:

$A$ photocell is a device that: