The correct answer is: B. Overall gain
Negative feedback is a technique used in electronic circuits to reduce the gain of an amplifier. This is done by feeding back a portion of the output signal to the input in such a way that it opposes the input signal. This has the effect of reducing the overall gain of the amplifier.
Band width is the range of frequencies that an amplifier can amplify without significant distortion. Distortion is the alteration of the shape of a signal as it passes through an amplifier. Instability is the tendency of an amplifier to oscillate, or produce an output signal that is not proportional to the input signal.
When negative feedback is introduced, the overall gain of the amplifier decreases. This is because the feedback signal opposes the input signal, and therefore reduces the amount of signal that is amplified. However, the band width and distortion of the amplifier are not affected by negative feedback. This is because the feedback signal is typically taken from a point after the amplifier’s output stage, and therefore does not affect the frequency response or distortion of the amplifier.
In conclusion, the correct answer is: B. Overall gain.