Correct option is B
The depletion layer in a p-n junction is the region where mobile charge carriers are depleted, leaving behind immobile ions.
Under reverse bias (when the p-side is connected to the negative terminal and the n-side to the positive terminal), the depletion layer widens because the reverse voltage opposes the flow of charge carriers, increasing the electric field and reducing current flow.
This widening of the depletion layer increases the junction's resistance to current flow, effectively reducing the leakage current in reverse bias.
