The correct answer is: B. Differential amplifier
A differential amplifier is an electronic amplifier that amplifies the difference between two input signals, while rejecting any common-mode signals that may be present on both inputs. This makes it ideal for use in applications where it is important to eliminate noise and interference, such as in the recording of bio signals.
A buffer amplifier is an amplifier that isolates a load from its driving source. This can be useful in applications where the driving source has a high output impedance, or where the load has a low input impedance. However, a buffer amplifier does not provide any common-mode rejection, so it is not suitable for use in the recording of bio signals.
A single-ended amplifier is an amplifier that has a single input signal. This type of amplifier is not suitable for use in the recording of bio signals, as it is susceptible to common-mode interference.
A chopper amplifier is a type of amplifier that uses a chopping technique to reduce noise. This type of amplifier is not commonly used in the recording of bio signals, as it is more complex and expensive than a differential amplifier.
In conclusion, a differential amplifier is the best choice for reducing common mode interference during recording of bio signals.