The correct answer is: D. Amplification.
An isolation amplifier is a device that isolates two circuits electrically, while allowing them to pass signals between them. This isolation is important in many applications, such as when one circuit is at a high voltage and the other is at a low voltage. Isolation amplifiers work by using transformers to convert the electrical signals from one circuit to another. The transformers are designed so that the output signal is not affected by the voltage difference between the two circuits.
Filtering is a process of removing unwanted frequencies from a signal. This can be done using a variety of methods, such as using a capacitor or an inductor. Attenuation is a process of reducing the amplitude of a signal. This can be done by using a resistor or a transformer. Clipping is a process of limiting the amplitude of a signal. This can be done by using a diode or a transistor.
In conclusion, the correct answer is: D. Amplification. Isolation amplifiers work by amplifying the signals from one circuit to another, while isolating the two circuits electrically.