Correct option is D
For a BJT to act as an amplifier, the preferred operating region is the "Linear" region, also known as the "Active" region.
Explanation:
Active region:
In this region, the BJT exhibits a linear relationship between the input current at the base and the output current at the collector, which is crucial for amplification.
Saturation region:
When a BJT is in saturation, it acts like a closed switch, not an amplifier.
Cutoff region:
In the cutoff region, the BJT acts like an open switch, again not suitable for amplification.
