The common mode gain is ___________

Answer: Option B

The common mode gain is very low.

Key Points:
Common Mode Gain: In an operational amplifier (op-amp), common mode gain refers to the gain applied to signals that are present on both the inverting and non-inverting inputs.
Purpose: For ideal op-amps, the common mode gain should be extremely low to ensure that the amplifier responds primarily to differential signals (the difference between the inverting and non-inverting inputs).
Practical Op-Amps: In real op-amps, although the common mode gain is not zero, it is minimized to enhance performance and accuracy in amplifying differential signals.