Analog Electronics - Engineering

Q1:

If a common emitter amplifier with an emitter resistance RC has an overall transconductance gain of 1 m A/V, a voltage gain of - 4 and desensitivity of 50, then the value of the emitter resistance R would be

A 50 kΩ

B 0.98 kΩ

C 50 Ω

D 0.98 Ω

ANS:B - 0.98 kΩ

Can anyone please help me solve this problem? Thank you.