Concept:A modem converts digital signals into analogue signals so that data can be transmitted over telephone lines.
Explanation:A computer produces digital signals made up of discrete binary values.
At the sending end, modem X modulates these digital signals into analogue signals suited for the telephone line.
The analogue signal then travels from modem X to modem Y through the transmission medium.
At the receiving end, modem Y demodulates the analogue signal back into a digital signal for the destination computer.
Hence, the signal moving between modem X and modem Y is in analogue form, while digital signals exist only at the computer-modem interfaces.
Answer:A. analogue
