According to Einstein's photoelectric equation to the graph between kinetic energy of photoelectrons ejected and the frequency of incident radiation is

The maximum kinetic energy of photoelectron ejected is given by $\mathrm{KE}=h \mathrm{v}-\phi_{0}=h \mathrm{v}-h \mathrm{v}_{0}=h\left(\mathrm{v}-\mathrm{v}_{0}\right)$ If the frequency of incident radiation is greater than threshold frequency $v_{0}$, then the ejection of photoelectrons starts. After that as frequency increases, kinetic energy also increases linearly. It is shown in option (d).