In the photoelectric effect experiment, electrons are ejected from the surface of a metal when light shines on it$.$ Which one or more of the following would lead to an increase in the maximum kinetic energy of the ejected electrons?

increasing the number of photons per second striking the surface

using photons whose frequency is less than $\frac{W_0}{h},$ where $W_0$ is the work function of the metal and $h$ is the Planck's constant

select a metal that has a smaller work function

select a metal that has a greater work function

increasing the frequency of the incident light