Final answer:
A direct coupled amplifier features wide frequency response, high voltage gain, and low distortion, because it uses DC coupling to pass signals directly between stages.
Step-by-step explanation:
The identifying feature(s) of a direct coupled amplifier include wide frequency response, high voltage gain, and low distortion. A direct coupled or DC amplifier uses direct current (DC) coupling between its stages to pass the signal directly, without any intervening capacitors or transformers, from one stage to the next. This coupling method avoids the frequency limitations imposed by capacitive or transformer coupling, thereby offering a wide frequency response. The use of DC coupling also helps to attain a high voltage gain since there are no intervening components to attenuate the signal. Finally, due to the absence of capacitors which can introduce phase shifts, a direct coupled amplifier typically has low distortion. The correct answer to the student's question is therefore "4) All of the above."