Which one of the following graph represents the variation of...

According to photoelectric equation $E_k=h v-h v_0$ ...(i) If the energy of photon $(h v)$ is less than the work function $\left(h v_0\right)$ of metallic surface, then electrons will never be ejected from surface regardless of intensity of incident light. Also, from Eq. (i), when $v=v_0, E_k=0 \therefore$ Graph (4) represents variation of $E_k$ with $v$.