I came across the following question:
A photon of energy $h\nu$ is absorbed by a free electron of a metal having work function $W<h\nu$. Then:
The electron is sure to come out
The electron is sure to come out with kinetic energy $h\nu-W$
Either the electron doesn't come out or it comes out with a kinetic energy $h\nu-W$
It may come out with kinetic energy less than $h\nu-W$
Both options 1. and 2. seem to be correct to me. However, the correct answer provided is 4.! How is this so? Isn't $W$ the amount of energy required for ejection of the most tightly bound electron in the metal? Then why is there a possibility that it won't come out with kinetic energy $h\nu-W$?