An amplifier without feedback has a voltage gain of 50, input resistance is 1 KΩ & Output resistance of 2.5KΩ.The input resistance of the current-shunt negative feedback amplifier using the above amplifier with a feedback factor of 0.2 is

• A. 1/11kΩ
• B. 1/5kΩ
• C. 5kΩ
• D. 11kΩ