Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R:
Assertion A: In the photoelectric effect, the electrons are ejected from the metal surface as soon as the beam of light of frequency greater than threshold frequency strikes the surface.
Reason R: When the photon of any energy strikes an electron in the atom, transfer of energy from the photon to the electron takes place.
In the light of the above statements, choose the most appropriate answer from the options given below:

Assertion A: In the photoelectric effect, electrons are ejected from the metal surface as soon as the beam of light of frequency greater than threshold frequency strikes the surface.

This is correct. The photoelectric effect is instantaneous when the frequency of incident light exceeds the threshold frequency.

Reason R: When the photon of any energy strikes an electron in the atom, transfer of energy from the photon to the electron takes place.

This is incorrect. Not any photon can cause energy transfer to eject electrons. The photon must have energy greater than or equal to the work function ($$h\nu \geq \phi$$) for the photoelectric effect to occur. Photons with energy less than the work function cannot eject electrons regardless of their intensity.

Therefore, A is correct but R is not correct.