The plot below shows best-fit lines for the average kinetic…

The plot below shows best-fit lines for the average kinetic energy of electrons ejected from the surface of two metal samples as a function of the frequency of the incident light.  The slope values of these best-fit lines provide an estimate of:   A. Planck’s constant, h B. The work function, W, of the metal C. The Wavelength of the ejected electron D. The speed of light, c