Introduction:
In voltage shut feedback amplifiers, the output voltage is fed back to the input in such a way that it opposes any change in the input voltage. This feedback mechanism is used to stabilize and control the gain of the amplifier. There are various special cases of voltage shut feedback amplifiers, each with its own characteristics and applications.

Voltage Follower:
A voltage follower, also known as a unity gain amplifier or a buffer, is a special case of voltage shut feedback amplifier. In a voltage follower, the output voltage follows the input voltage, hence the name. The voltage gain of a voltage follower is unity, which means the output voltage is the same as the input voltage.

Current to Voltage Converter:
A current to voltage converter, also known as a transimpedance amplifier, is another special case of voltage shut feedback amplifier. It converts an input current into an output voltage. The output voltage is proportional to the input current, and the proportionality constant is determined by the feedback resistor.

Inverter:
An inverter, also known as an inverting amplifier, is a special case of voltage shut feedback amplifier where the output voltage is the inverse of the input voltage. The inverter has a negative voltage gain, which means it amplifies the input voltage with an opposite polarity. The voltage gain is determined by the feedback resistor and the input resistor.

Explanation:
The correct answer is option 'A', voltage follower. A voltage follower is not a special case of voltage shut feedback amplifier. It is a basic amplifier configuration where the output voltage is directly connected to the input. There is no feedback mechanism involved in a voltage follower, and the gain is unity. It is mainly used to isolate the input signal from the load and provide high input impedance.

Conclusion:
In summary, the special cases of voltage shut feedback amplifiers include voltage follower, current to voltage converter, and inverter. These configurations have different characteristics and applications. The voltage follower is not a special case of voltage shut feedback amplifier as it does not involve any feedback mechanism.