The result of changing a physical sound wave into an analogous electrical signal using a transducer (such as a microphone) is called

The result of changing a physical sound wave into an analogous electrical signal using a transducer (such as a microphone) is called analogue audio. In this system, the rapid electrical level is directly proportional to the rapid air pressure taken by the transducer. The analogue signal is then augmented and can be kept on an analogue medium such as tape or transformed further into a succession of discrete mathematical numbers. The advantages of using this device is that it yields a subtle sound and is pleasing to the ear by pushing the signal level and overdriving it. But the disadvantages are editing it would be tedious and prone to degradation.

real, smaller and upside-down.   so the answer should be b.