In the circuit shown in figure is a finite gain amplifier with a gain of K, a very large input impedance, and a very low output impedance. The input impedance of the feedback amplifier with the feedback impedance Z connected as shown will be

A. $${\text{Z}}\left[ {1 - \frac{1}{{\text{K}}}} \right]$$

B. $${\text{Z}}\left( {1 - {\text{K}}} \right)$$

C. $$\left[ {\frac{{\text{Z}}}{{{\text{K}} - 1}}} \right]$$

D. $$\left[ {\frac{{\text{Z}}}{{1 - {\text{K}}}}} \right]$$

Answer: Option D