How much resistance does a diode have in reverse bias?

In reverse bias, a diode presents a high resistance to the flow of current. This characteristic is essential for the operation of diodes, as it allows them to block current in the reverse direction while conducting current in the forward direction. When a diode is reverse-biased, it means that the voltage applied across the diode is in the opposite direction of its conduction, typically resulting in a small leakage current that is negligible compared to the forward current. This high resistance is what prevents significant current from flowing through the diode in the reverse direction, thereby providing protection in circuits and ensuring proper functionality in applications such as rectifiers and voltage regulators.

The other options suggest resistance that does not align with the behavior of a diode in reverse bias, such as low resistance, neutrality, or zero resistance, which are not characteristics of diodes in this condition.