When a transistor is biased such that its Base current is greater than zero and its collector-to-emitter voltage is less than 0.2 V, it is operating in the ______ region.

The correct region of operation is the saturation region.

Concept:

In a bipolar junction transistor (BJT), there are three main operating regions:

1) Cut-off: In this zone, both the base-emitter junction and the base-collector junction are reverse-biased. The transistor is considered to be off, doesn't conduct current (or conducts very minimal leakage current), and acts essentially like an open circuit.

2) Active (or linear): In this region, the base-emitter junction is forward-biased and the base-collector junction is reverse-biased. The transistor conducts current and can amplify signals. It's in this region that the transistor is typically used as an amplifier.

3) Saturation: In this region, both the base-emitter and the base-collector junctions are forward-biased. The transistor is fully on, allows maximum current to flow from collector to emitter, and acts like a closed switch.

When the base current is greater than zero, it means the base-emitter junction is forward-biased, ruling out the cut-off region. If the collector-to-emitter voltage is less than 0.2 V, it suggests that it's too low to be in the active region (where it's usually higher), so the transistor is likely in saturation, which typically corresponds to a very low (close to zero) collector-emitter voltage.