An amplifier has input impedance of 4 kΩ and output impedance of 80 kΩ. It is used in negative feedback circuit with 10% feedback. If open loop gain is 90, the closed loop input and output impedances are

• A. 40 kΩ and 8 kΩ respectively
• B. 4 kΩ and 80 kΩ respectively
• C. 0.4 kΩ and 800 kΩ respectively
• D. 8 kΩ and 160 kΩ respectively