Potential across the junction varies symmetrically linear, having side negative and side positive. We know that in a forward biased junction diode, the repulsion of holes and electrons takes place which decreases width of potential barrier by striking the combination of holes and electrons. We also know that the options and show the potential barrier in the reverse bias, whereas in options and show the potential barrier in forward bias. Moreover, the width of depletion layer in option is less than shown in option . Thus, the option is correct.