Final answer:
The progression of a signal in an ultrasound machine is from the transducer to the receiver, then to the scan converter, and finally to the display, where an image is produced.
Step-by-step explanation:
The correct progression in which a signal moves through an ultrasound machine is: Transducer, Receiver, Scan Converter, Display. First, the transducer acts as both a transmitter and a receiver of the ultrasonic waves. It emits high-frequency sound waves that travel through tissue and then records the echoes reflected from various boundaries within the body. Next, the receiver processes these echoes, amplifying and filtering the signals. The scan converter then takes these electrical signals and converts them into a digital form that can be used by a computer to create an image. This processed data is then sent to the display, where a two-dimensional image is produced, visualizing the area of interest such as internal body structures during medical examinations.