The correct answer is: B. Delays the signals.
An amplifier is a device that increases the amplitude of a signal. The gain of an amplifier is the ratio of the output signal amplitude to the input signal amplitude. The response time of an amplifier is the time it takes for the output signal to reach a steady state after a change in the input signal.
If the response time of an amplifier is too long, it will cause the signals to be delayed. This can be a problem in biomedical recorders, as it can make it difficult to accurately measure the time between events.
The other options are incorrect. The gain of an amplifier is not affected by the response time. The shape of the waveform of the signal is not affected by the response time, unless the response time is very long. The attenuation of the signals is not affected by the response time.